{ "query": { "display": "$$y^{^{\\prime\\prime}}+36y=-60\\sec\\left(6t\\right)$$", "symbolab_question": "ODE#y^{\\prime \\prime }+36y=-60\\sec(6t)" }, "solution": { "level": "PERFORMED", "subject": "Calculus", "topic": "ODE", "subTopic": "ConstCoeffLinearNonHomogeneous", "default": "y=c_{1}\\cos(6t)+c_{2}\\sin(6t)-\\frac{5}{3}\\ln(\\cos(6t))\\cos(6t)-10t\\sin(6t)", "meta": { "showVerify": true } }, "steps": { "type": "interim", "title": "$$y^{\\prime\\prime}\\left(t\\right)+36y=-60\\sec\\left(6t\\right):{\\quad}y=c_{1}\\cos\\left(6t\\right)+c_{2}\\sin\\left(6t\\right)-\\frac{5}{3}\\ln\\left(\\cos\\left(6t\\right)\\right)\\cos\\left(6t\\right)-10t\\sin\\left(6t\\right)$$", "input": "y^{\\prime\\prime}\\left(t\\right)+36y=-60\\sec\\left(6t\\right)", "steps": [ { "type": "interim", "title": "Solve linear ODE:$${\\quad}y=c_{1}\\cos\\left(6t\\right)+c_{2}\\sin\\left(6t\\right)-\\frac{5}{3}\\ln\\left(\\cos\\left(6t\\right)\\right)\\cos\\left(6t\\right)-10t\\sin\\left(6t\\right)$$", "input": "y^{\\prime\\prime}\\left(t\\right)+36y=-60\\sec\\left(6t\\right)", "steps": [ { "type": "definition", "title": "Second order linear non-homogeneous differential equation with constant coefficients", "text": "A second order linear, non-homogeneous ODE has the form of $$ay''+by'+cy=g\\left(x\\right)$$" }, { "type": "step", "primary": "The general solution to $$a\\left(x\\right)y''+b\\left(x\\right)y'+c\\left(x\\right)y=g\\left(x\\right)$$ can be written as<br/>$$y=y_h+y_p$$<br/>$$y_h$$ is the solution to the homogeneous ODE $$a\\left(x\\right)y''+b\\left(x\\right)y'+c\\left(x\\right)y=0$$<br/>$$y_p$$, the particular solution, is any function that satisfies the non-homogeneous equation " }, { "type": "interim", "title": "Find $$y_h$$ by solving $$y^{\\prime\\prime}\\left(t\\right)+36y=0:{\\quad}y=c_{1}\\cos\\left(6t\\right)+c_{2}\\sin\\left(6t\\right)$$", "input": "y^{\\prime\\prime}\\left(t\\right)+36y=0", "steps": [ { "type": "definition", "title": "Second order linear homogeneous differential equation with constant coefficients", "text": "A second order linear, homogeneous ODE has the form of $$ay''+by'+cy=0$$" }, { "type": "step", "primary": "For an equation $$ay''+by'+cy=0$$, assume a solution of the form $$e^{γt}$$", "secondary": [ "Rewrite the equation with $$y=e^{γt}$$" ], "result": "\\left(\\left(e^{γt}\\right)\\right)^{^{\\prime\\prime}}+36e^{γt}=0" }, { "type": "interim", "title": "Simplify $$\\left(\\left(e^{γt}\\right)\\right)^{\\prime\\prime}+36e^{γt}=0:{\\quad}e^{γt}\\left(γ^{2}+36\\right)=0$$", "steps": [ { "type": "step", "result": "\\left(\\left(e^{γt}\\right)\\right)^{^{\\prime\\prime}}+36e^{γt}=0" }, { "type": "interim", "title": "$$\\left(e^{γt}\\right)^{\\prime\\prime}=γ^{2}e^{γt}$$", "input": "\\left(e^{γt}\\right)^{\\prime\\prime}", "steps": [ { "type": "interim", "title": "$$\\left(e^{γt}\\right)^{\\prime}=e^{γt}γ$$", "input": "\\left(e^{γt}\\right)^{\\prime}", "steps": [ { "type": "interim", "title": "Apply the chain rule:$${\\quad}e^{γt}\\left(γt\\right)^{\\prime}$$", "input": "\\left(e^{γt}\\right)^{\\prime}", "result": "=e^{γt}\\left(γt\\right)^{\\prime}", "steps": [ { "type": "step", "primary": "Apply the chain rule: $$\\frac{df\\left(u\\right)}{dx}=\\frac{df}{du}\\cdot\\frac{du}{dx}$$", "secondary": [ "$$f=e^{u},\\:\\:u=γt$$" ], "result": "=\\left(e^{u}\\right)^{^{\\prime}}\\left(γt\\right)^{^{\\prime}}", "meta": { "practiceLink": "/practice/derivatives-practice#area=main&subtopic=Chain%20Rule", "practiceTopic": "Chain Rule" } }, { "type": "interim", "title": "$$\\left(e^{u}\\right)^{\\prime}=e^{u}$$", "input": "\\left(e^{u}\\right)^{\\prime}", "steps": [ { "type": "step", "primary": "Apply the common derivative: $$\\left(e^{u}\\right)^{\\prime}=e^{u}$$", "result": "=e^{u}" } ], "meta": { "solvingClass": "Derivatives", "interimType": "Derivatives", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7cVPV4zUFISiTd+fVX6xXsrmsNRuddYPgZ8cGsLVhNNRQsU0KegSjwRVV1JfeZUqosl5PTRzFd2J0fcq0+01bpNW4Yoa9OGLIL+u1HBPyzhvQzhwSHylow7u2/8ADWpoHsIjaxJ4DvjTb2fbKjbvtlQ==" } }, { "type": "step", "result": "=e^{u}\\left(γt\\right)^{^{\\prime}}" }, { "type": "step", "primary": "Substitute back $$u=γt$$", "result": "=e^{γt}\\left(γt\\right)^{^{\\prime}}" } ], "meta": { "interimType": "Derivative Chain Rule 0Eq", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7Gvl9rbrp9vJgB3DE3RVCcDDfSBXef41nZ6zbP7ViaAosjvX7KVUO/AeCFSId4S33iWw9g5uXzmS5KX5zIzOHZXiX35dQ/h01lIvxamZtt5PvoGisVaN+BwjjtpPeRZCLDrbw8lc2jRiiaaodUFzB+wS4M5VpC8qh+oehjmM1qmzPHVJGaR3CuIp5NX3rLDDQialcV/dI5TH4fXyp+ncwuA==" } }, { "type": "interim", "title": "$$\\left(γt\\right)^{\\prime}=γ$$", "input": "\\left(γt\\right)^{\\prime}", "steps": [ { "type": "step", "primary": "Take the constant out: $$\\left(a{\\cdot}f\\right)'=a{\\cdot}f'$$", "result": "=γt^{^{\\prime}}" }, { "type": "step", "primary": "Apply the common derivative: $$t^{\\prime}=1$$", "result": "=γ\\cdot\\:1" }, { "type": "step", "primary": "Simplify", "result": "=γ", "meta": { "solvingClass": "Solver" } } ], "meta": { "solvingClass": "Derivatives", "interimType": "Derivatives", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7stv4XdlIkdSrTZc5soZLGCENAk/2SHMUCwaiey+GXBFDkFJVC/dxv52FMorbXyXoUpO3zWZspTvnswNQKdz3tSbX/i/cqXdrp84USJNBCUvvRCDs4D3rcIVpx7C72k9c" } }, { "type": "step", "result": "=e^{γt}γ" } ], "meta": { "solvingClass": "Derivatives", "interimType": "Derivatives" } }, { "type": "step", "result": "=\\left(e^{γt}γ\\right)^{^{\\prime}}" }, { "type": "interim", "title": "$$\\left(e^{γt}γ\\right)^{\\prime}=γ^{2}e^{γt}$$", "input": "\\left(e^{γt}γ\\right)^{\\prime}", "steps": [ { "type": "step", "primary": "Take the constant out: $$\\left(a{\\cdot}f\\right)'=a{\\cdot}f'$$", "result": "=γ\\left(e^{γt}\\right)^{^{\\prime}}" }, { "type": "interim", "title": "Apply the chain rule:$${\\quad}e^{γt}\\left(γt\\right)^{\\prime}$$", "input": "\\left(e^{γt}\\right)^{\\prime}", "result": "=e^{γt}\\left(γt\\right)^{\\prime}", "steps": [ { "type": "step", "primary": "Apply the chain rule: $$\\frac{df\\left(u\\right)}{dx}=\\frac{df}{du}\\cdot\\frac{du}{dx}$$", "secondary": [ "$$f=e^{u},\\:\\:u=γt$$" ], "result": "=\\left(e^{u}\\right)^{^{\\prime}}\\left(γt\\right)^{^{\\prime}}", "meta": { "practiceLink": "/practice/derivatives-practice#area=main&subtopic=Chain%20Rule", "practiceTopic": "Chain Rule" } }, { "type": "interim", "title": "$$\\left(e^{u}\\right)^{\\prime}=e^{u}$$", "input": "\\left(e^{u}\\right)^{\\prime}", "steps": [ { "type": "step", "primary": "Apply the common derivative: $$\\left(e^{u}\\right)^{\\prime}=e^{u}$$", "result": "=e^{u}" } ], "meta": { "solvingClass": "Derivatives", "interimType": "Derivatives", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7cVPV4zUFISiTd+fVX6xXsrmsNRuddYPgZ8cGsLVhNNRQsU0KegSjwRVV1JfeZUqosl5PTRzFd2J0fcq0+01bpNW4Yoa9OGLIL+u1HBPyzhvQzhwSHylow7u2/8ADWpoHsIjaxJ4DvjTb2fbKjbvtlQ==" } }, { "type": "step", "result": "=e^{u}\\left(γt\\right)^{^{\\prime}}" }, { "type": "step", "primary": "Substitute back $$u=γt$$", "result": "=e^{γt}\\left(γt\\right)^{^{\\prime}}" } ], "meta": { "interimType": "Derivative Chain Rule 0Eq", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7Gvl9rbrp9vJgB3DE3RVCcDDfSBXef41nZ6zbP7ViaAosjvX7KVUO/AeCFSId4S33iWw9g5uXzmS5KX5zIzOHZXiX35dQ/h01lIvxamZtt5PvoGisVaN+BwjjtpPeRZCLDrbw8lc2jRiiaaodUFzB+wS4M5VpC8qh+oehjmM1qmzPHVJGaR3CuIp5NX3rLDDQialcV/dI5TH4fXyp+ncwuA==" } }, { "type": "interim", "title": "$$\\left(γt\\right)^{\\prime}=γ$$", "input": "\\left(γt\\right)^{\\prime}", "steps": [ { "type": "step", "primary": "Take the constant out: $$\\left(a{\\cdot}f\\right)'=a{\\cdot}f'$$", "result": "=γt^{^{\\prime}}" }, { "type": "step", "primary": "Apply the common derivative: $$t^{\\prime}=1$$", "result": "=γ\\cdot\\:1" }, { "type": "step", "primary": "Simplify", "result": "=γ", "meta": { "solvingClass": "Solver" } } ], "meta": { "solvingClass": "Derivatives", "interimType": "Derivatives", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7stv4XdlIkdSrTZc5soZLGCENAk/2SHMUCwaiey+GXBFDkFJVC/dxv52FMorbXyXoUpO3zWZspTvnswNQKdz3tSbX/i/cqXdrp84USJNBCUvvRCDs4D3rcIVpx7C72k9c" } }, { "type": "step", "result": "=γe^{γt}γ" }, { "type": "interim", "title": "Simplify $$γe^{γt}γ:{\\quad}γ^{2}e^{γt}$$", "input": "γe^{γt}γ", "result": "=γ^{2}e^{γt}", "steps": [ { "type": "step", "primary": "Apply exponent rule: $$a^b\\cdot\\:a^c=a^{b+c}$$", "secondary": [ "$$γγ=\\:γ^{1+1}$$" ], "result": "=e^{γt}γ^{1+1}", "meta": { "practiceLink": "/practice/exponent-practice", "practiceTopic": "Expand FOIL" } }, { "type": "step", "primary": "Add the numbers: $$1+1=2$$", "result": "=e^{γt}γ^{2}" } ], "meta": { "solvingClass": "Solver", "interimType": "Generic Simplify Specific 1Eq", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7riofKsRQ/FkpZv0BW2pxMd6GQqufR6tr2vPxOUv7H+/BWItNlNCsjK5QfFqGTa8umx4rCXhbsN+br+uOYP22UU3kCh3oevUunZ7/b0qFKBStCRMtul5SOs/SBwPTbaWuo4bl40YraHWFXpFVaYGPXg==" } } ], "meta": { "solvingClass": "Derivatives", "interimType": "Derivatives" } }, { "type": "step", "result": "=γ^{2}e^{γt}" } ], "meta": { "solvingClass": "Derivatives", "interimType": "Derivatives" } }, { "type": "step", "result": "γ^{2}e^{γt}+36e^{γt}=0" }, { "type": "step", "primary": "Factor $$e^{γt}$$", "result": "e^{γt}\\left(γ^{2}+36\\right)=0" } ], "meta": { "interimType": "Generic Simplify Specific 1Eq" } }, { "type": "step", "result": "e^{γt}\\left(γ^{2}+36\\right)=0" }, { "type": "interim", "title": "Solve $$e^{γt}\\left(γ^{2}+36\\right)=0:{\\quad}γ=6i,\\:γ=-6i$$", "input": "e^{γt}\\left(γ^{2}+36\\right)=0", "steps": [ { "type": "step", "primary": "Since $$e^{γt}\\ne\\:0$$, solving $$e^{γt}\\left(γ^{2}+36\\right)=0$$<br/> is equivalent to solving the quadratic equation $$γ^{2}+36=0$$", "result": "γ^{2}+36=0" }, { "type": "interim", "title": "Move $$36\\:$$to the right side", "input": "γ^{2}+36=0", "result": "γ^{2}=-36", "steps": [ { "type": "step", "primary": "Subtract $$36$$ from both sides", "result": "γ^{2}+36-36=0-36" }, { "type": "step", "primary": "Simplify", "result": "γ^{2}=-36" } ], "meta": { "interimType": "Move to the Right Title 1Eq", "gptData": "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" } }, { "type": "step", "primary": "For $$x^{2}=f\\left(a\\right)$$ the solutions are $$x=\\sqrt{f\\left(a\\right)},\\:\\:-\\sqrt{f\\left(a\\right)}$$" }, { "type": "step", "result": "γ=\\sqrt{-36},\\:γ=-\\sqrt{-36}" }, { "type": "interim", "title": "$$\\sqrt{-36}=6i$$", "input": "\\sqrt{-36}", "steps": [ { "type": "step", "primary": "Apply radical rule: $$\\sqrt{-a}=\\sqrt{a}\\sqrt{-1}$$", "secondary": [ "$$\\sqrt{-36}=\\sqrt{36}\\sqrt{-1}$$" ], "result": "=\\sqrt{36}\\sqrt{-1}", "meta": { "practiceLink": "/practice/radicals-practice", "practiceTopic": "Radical Rules" } }, { "type": "step", "primary": "Apply imaginary number rule: $$\\sqrt{-1}=i$$", "result": "=\\sqrt{36}i", "meta": { "practiceLink": "/practice/complex-numbers-practice", "practiceTopic": "Expand FOIL" } }, { "type": "interim", "title": "$$\\sqrt{36}=6$$", "input": "\\sqrt{36}", "steps": [ { "type": "step", "primary": "Factor the number: $$36=6^{2}$$", "result": "=\\sqrt{6^{2}}" }, { "type": "step", "primary": "Apply radical rule: $$\\sqrt{a^2}=a,\\:\\quad\\:a\\ge0$$", "secondary": [ "$$\\sqrt{6^{2}}=6$$" ], "result": "=6" } ], "meta": { "solvingClass": "Solver2", "interimType": "Solver2", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7ba5g+UZ5roMy68ii/TX6lSAn9lkDfZkicUGkO3EF+IowGPWQQxj+Buy70vvMPVbRzGQBGgzjhY9wy62Ypaxu7DP9zNOAin/+9QrppOujlp4=" } }, { "type": "step", "result": "=6i" } ], "meta": { "solvingClass": "Solver2", "interimType": "Solver2", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7oGU6sXD51uYqrDyiC7DJKN6GQqufR6tr2vPxOUv7H+9bQPAhKkRHwQtN722Vq170hj6ylSwHjJkmQPKH34+7f/Q9J8iednviAQ8XqKUxpSA=" } }, { "type": "interim", "title": "$$-\\sqrt{-36}=-6i$$", "input": "-\\sqrt{-36}", "steps": [ { "type": "step", "primary": "Apply radical rule: $$\\sqrt{-a}=\\sqrt{a}\\sqrt{-1}$$", "secondary": [ "$$-\\sqrt{-36}=-\\sqrt{36}\\sqrt{-1}$$" ], "result": "=-\\sqrt{36}\\sqrt{-1}", "meta": { "practiceLink": "/practice/radicals-practice", "practiceTopic": "Radical Rules" } }, { "type": "step", "primary": "Apply imaginary number rule: $$\\sqrt{-1}=i$$", "result": "=-\\sqrt{36}i", "meta": { "practiceLink": "/practice/complex-numbers-practice", "practiceTopic": "Expand FOIL" } }, { "type": "interim", "title": "$$\\sqrt{36}=6$$", "input": "\\sqrt{36}", "steps": [ { "type": "step", "primary": "Factor the number: $$36=6^{2}$$", "result": "=\\sqrt{6^{2}}" }, { "type": "step", "primary": "Apply radical rule: $$\\sqrt{a^2}=a,\\:\\quad\\:a\\ge0$$", "secondary": [ "$$\\sqrt{6^{2}}=6$$" ], "result": "=6" } ], "meta": { "solvingClass": "Solver2", "interimType": "Solver2", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7ba5g+UZ5roMy68ii/TX6lSAn9lkDfZkicUGkO3EF+IowGPWQQxj+Buy70vvMPVbRzGQBGgzjhY9wy62Ypaxu7DP9zNOAin/+9QrppOujlp4=" } }, { "type": "step", "result": "=-6i" } ], "meta": { "solvingClass": "Solver2", "interimType": "Solver2", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7A/rlP7B78aIdO/PL1Tz02VXTSum/z5kLpMzXS1UJIeyj0KG0lvFYbYVov0nziiPsCXP3HRkwvQo8XuRFa/NQF7WRjDkGr5D0b3lZyvYbjrUkt3WiGR7ZaCaXvz77bMjS" } }, { "type": "step", "result": "γ=6i,\\:γ=-6i" } ], "meta": { "interimType": "Generic Solve Title 1Eq" } }, { "type": "step", "result": "γ=6i,\\:γ=-6i" }, { "type": "step", "primary": "For two complex roots $$γ_{1}\\ne\\:γ_{2}$$, where $$γ_{1}=\\alpha+i\\:\\beta,\\:γ_{2}=\\alpha-i\\:\\beta\\:$$<br/>the general solution takes the form:$${\\quad}y=e^{\\alpha\\:t}\\left(c_{1}\\cos\\left(\\beta\\:t\\right)+c_{2}\\sin\\left(\\beta\\:t\\right)\\right)$$", "result": "e^{0}\\left(c_{1}\\cos\\left(6t\\right)+c_{2}\\sin\\left(6t\\right)\\right)" }, { "type": "step", "primary": "Simplify", "result": "y=c_{1}\\cos\\left(6t\\right)+c_{2}\\sin\\left(6t\\right)" } ], "meta": { "solvingClass": "ODE", "interimType": "Generic Find By Solving Title 2Eq" } }, { "type": "interim", "title": "Find $$y_{p}$$ that satisfies $$y^{\\prime\\prime}\\left(t\\right)+36y=-60\\sec\\left(6t\\right):{\\quad}y_{p}=-\\frac{5}{3}\\ln\\left(\\cos\\left(6t\\right)\\right)\\cos\\left(6t\\right)-10t\\sin\\left(6t\\right)$$", "steps": [ { "type": "step", "primary": "For the non-homogeneous part $$g\\left(t\\right)=-60\\sec\\left(6t\\right)$$, assume a solution of the form:<br/>$$y_{p}=u_{1}y_{1}+u_{2}y_{2}$$<br/>Where $$y_{1}$$ and $$y_{2}$$ are solutions of homogeneous equation $$y_{h}=c_{1}y_{1}+c_{2}y_{2}$$, <br/> $${u_{1}}$$ and $${u_{2}}$$ are solutions to the system of equations:<br/>$$\\begin{pmatrix}\\left(u_{1}\\right)^{^{\\prime}}y_{1}+\\left(u_{2}\\right)^{^{\\prime}}y_{2}=0\\\\\\left(u_{1}\\right)^{^{\\prime}}\\left(y_{1}\\right)^{^{\\prime}}+\\left(u_{2}\\right)^{^{\\prime}}\\left(y_{2}\\right)^{^{\\prime}}=g\\left(t\\right)\\end{pmatrix}$$<br/>Which implies", "secondary": [ "$$u_{1}=\\int\\:-\\frac{y_{2}g\\left(t\\right)}{W\\left(y_{1},\\:y_{2}\\right)}dt$$", "$$u_{2}=\\int\\:\\frac{y_{1}g\\left(t\\right)}{W\\left(y_{1},\\:y_{2}\\right)}dt$$", "Where Wronskian $$W\\left(y_{1},\\:y_{2}\\right)=y_{1}\\left(y_{2}\\right)^{^{\\prime}}-\\left(y_{1}\\right)^{^{\\prime}}y_{2}$$" ] }, { "type": "step", "primary": "Homogeneous solutions:", "secondary": [ "$$y_{1}=\\cos\\left(6t\\right)$$", "$$y_{2}=\\sin\\left(6t\\right)$$" ] }, { "type": "interim", "title": "$$\\left(y_{1}\\right)^{^{\\prime}}:{\\quad}-\\sin\\left(6t\\right)\\cdot\\:6$$", "input": "\\left(\\cos\\left(6t\\right)\\right)^{\\prime}", "steps": [ { "type": "interim", "title": "Apply the chain rule:$${\\quad}-\\sin\\left(6t\\right)\\left(6t\\right)^{\\prime}$$", "input": "\\left(\\cos\\left(6t\\right)\\right)^{\\prime}", "result": "=-\\sin\\left(6t\\right)\\left(6t\\right)^{\\prime}", "steps": [ { "type": "step", "primary": "Apply the chain rule: $$\\frac{df\\left(u\\right)}{dx}=\\frac{df}{du}\\cdot\\frac{du}{dx}$$", "secondary": [ "$$f=\\cos\\left(u\\right),\\:\\:u=6t$$" ], "result": "=\\left(\\cos\\left(u\\right)\\right)^{^{\\prime}}\\left(6t\\right)^{^{\\prime}}", "meta": { "practiceLink": "/practice/derivatives-practice#area=main&subtopic=Chain%20Rule", "practiceTopic": "Chain Rule" } }, { "type": "interim", "title": "$$\\left(\\cos\\left(u\\right)\\right)^{\\prime}=-\\sin\\left(u\\right)$$", "input": "\\left(\\cos\\left(u\\right)\\right)^{\\prime}", "steps": [ { "type": "step", "primary": "Apply the common derivative: $$\\left(\\cos\\left(u\\right)\\right)^{\\prime}=-\\sin\\left(u\\right)$$", "result": "=-\\sin\\left(u\\right)" } ], "meta": { "solvingClass": "Derivatives", "interimType": "Derivatives", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7aJtZOJKzwzgX3sX8vWzwyLRGYgE/Uo1dnewG4GHneMqXIQHgliMhSOSNsNni19In4/yNG6RtaMeFUKXMVc75z2DpznShoZau34eGycg+7G3mVcoSp6dsHpd9bDcXuJ0pz2gvuHI/drUkZ7NmziNx4SS3daIZHtloJpe/PvtsyNI=" } }, { "type": "step", "result": "=-\\sin\\left(u\\right)\\left(6t\\right)^{^{\\prime}}" }, { "type": "step", "primary": "Substitute back $$u=6t$$", "result": "=-\\sin\\left(6t\\right)\\left(6t\\right)^{^{\\prime}}" } ], "meta": { "interimType": "Derivative Chain Rule 0Eq", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7aJtZOJKzwzgX3sX8vWzwyIu/GYkmDFNPqT12rKBwQ9JJQz2lqSQogu9PoWz88zfnZQ9Z3Siv7iLdHqZDfvh55mmSkC3Mw9EDaBd1JKNjy8RLUkD296vqd81SRk8bq7AlJcj6EQVgLle9yFp8cy8qck3kCh3oevUunZ7/b0qFKBSgKzM+BlIedhng7m5DQQLWtIFBygoY9STUrg+h4aNkjw==" } }, { "type": "interim", "title": "$$\\left(6t\\right)^{\\prime}=6$$", "input": "\\left(6t\\right)^{\\prime}", "steps": [ { "type": "step", "primary": "Take the constant out: $$\\left(a{\\cdot}f\\right)'=a{\\cdot}f'$$", "result": "=6t^{^{\\prime}}" }, { "type": "step", "primary": "Apply the common derivative: $$t^{\\prime}=1$$", "result": "=6\\cdot\\:1" }, { "type": "step", "primary": "Simplify", "result": "=6", "meta": { "solvingClass": "Solver" } } ], "meta": { "solvingClass": "Derivatives", "interimType": "Derivatives", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7zgsQLHKcE4bPMk/tfhJr3MPQlVFV646ejpUuEWqujX2QuIxj9K+Upo9l4tAcwN/gV29r656qFR0DUTLPqu9PtMnS+huczlXBlThLcwNi14o7wEWcvxYk7LAulItRhl3H" } }, { "type": "step", "result": "=-\\sin\\left(6t\\right)\\cdot\\:6" } ], "meta": { "solvingClass": "Derivatives", "interimType": "Derivatives" } }, { "type": "interim", "title": "$$\\left(y_{2}\\right)^{^{\\prime}}:{\\quad}\\cos\\left(6t\\right)\\cdot\\:6$$", "input": "\\left(\\sin\\left(6t\\right)\\right)^{\\prime}", "steps": [ { "type": "interim", "title": "Apply the chain rule:$${\\quad}\\cos\\left(6t\\right)\\left(6t\\right)^{\\prime}$$", "input": "\\left(\\sin\\left(6t\\right)\\right)^{\\prime}", "result": "=\\cos\\left(6t\\right)\\left(6t\\right)^{\\prime}", "steps": [ { "type": "step", "primary": "Apply the chain rule: $$\\frac{df\\left(u\\right)}{dx}=\\frac{df}{du}\\cdot\\frac{du}{dx}$$", "secondary": [ "$$f=\\sin\\left(u\\right),\\:\\:u=6t$$" ], "result": "=\\left(\\sin\\left(u\\right)\\right)^{^{\\prime}}\\left(6t\\right)^{^{\\prime}}", "meta": { "practiceLink": "/practice/derivatives-practice#area=main&subtopic=Chain%20Rule", "practiceTopic": "Chain Rule" } }, { "type": "interim", "title": "$$\\left(\\sin\\left(u\\right)\\right)^{\\prime}=\\cos\\left(u\\right)$$", "input": "\\left(\\sin\\left(u\\right)\\right)^{\\prime}", "steps": [ { "type": "step", "primary": "Apply the common derivative: $$\\left(\\sin\\left(u\\right)\\right)^{\\prime}=\\cos\\left(u\\right)$$", "result": "=\\cos\\left(u\\right)" } ], "meta": { "solvingClass": "Derivatives", "interimType": "Derivatives", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7zq/dS8/GgjeXPl0DU/przbRGYgE/Uo1dnewG4GHneMqXIQHgliMhSOSNsNni19InMhwrDgcALtDbcjUqULjO0e5byrQDQVCXUD0vH/fvOdy0Sv9DakosoaSdvz3y7/jiRKGGP17LApxwbbz9SLndow==" } }, { "type": "step", "result": "=\\cos\\left(u\\right)\\left(6t\\right)^{^{\\prime}}" }, { "type": "step", "primary": "Substitute back $$u=6t$$", "result": "=\\cos\\left(6t\\right)\\left(6t\\right)^{^{\\prime}}" } ], "meta": { "interimType": "Derivative Chain Rule 0Eq", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7zq/dS8/GgjeXPl0DU/przYu/GYkmDFNPqT12rKBwQ9JJQz2lqSQogu9PoWz88zfnZQ9Z3Siv7iLdHqZDfvh55mmSkC3Mw9EDaBd1JKNjy8STo/r9qs40dtZcwt9pfTzzV9kLmPuggiAJDvGg3AtI9KqQhfqSx4Ip0S2H5wgufDIxf2pgqTS+Ia9coexBJUV6iL5k+VDooFqbSQg5EE31pQ==" } }, { "type": "interim", "title": "$$\\left(6t\\right)^{\\prime}=6$$", "input": "\\left(6t\\right)^{\\prime}", "steps": [ { "type": "step", "primary": "Take the constant out: $$\\left(a{\\cdot}f\\right)'=a{\\cdot}f'$$", "result": "=6t^{^{\\prime}}" }, { "type": "step", "primary": "Apply the common derivative: $$t^{\\prime}=1$$", "result": "=6\\cdot\\:1" }, { "type": "step", "primary": "Simplify", "result": "=6", "meta": { "solvingClass": "Solver" } } ], "meta": { "solvingClass": "Derivatives", "interimType": "Derivatives", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7zgsQLHKcE4bPMk/tfhJr3MPQlVFV646ejpUuEWqujX2QuIxj9K+Upo9l4tAcwN/gV29r656qFR0DUTLPqu9PtMnS+huczlXBlThLcwNi14o7wEWcvxYk7LAulItRhl3H" } }, { "type": "step", "result": "=\\cos\\left(6t\\right)\\cdot\\:6" } ], "meta": { "solvingClass": "Derivatives", "interimType": "Derivatives" } }, { "type": "step", "primary": "$$W\\left(y_{1},\\:y_{2}\\right)=y_{1}\\left(y_{2}\\right)^{^{\\prime}}-\\left(y_{1}\\right)^{^{\\prime}}y_{2}$$", "result": "W\\left(y_{1},\\:y_{2}\\right)=\\cos\\left(6t\\right)\\cos\\left(6t\\right)\\cdot\\:6-\\left(-\\sin\\left(6t\\right)\\cdot\\:6\\right)\\sin\\left(6t\\right)" }, { "type": "step", "result": "W\\left(y_{1},\\:y_{2}\\right)=6" }, { "type": "step", "primary": "$$u_{1}=\\int\\:-\\frac{y_{2}g\\left(t\\right)}{W\\left(y_{1},\\:y_{2}\\right)}dt$$", "result": "u_{1}=\\int\\:-\\frac{\\sin\\left(6t\\right)\\left(-60\\sec\\left(6t\\right)\\right)}{6}dt" }, { "type": "interim", "title": "$$\\int\\:-\\frac{\\sin\\left(6t\\right)\\left(-60\\sec\\left(6t\\right)\\right)}{6}dt=-\\frac{5}{3}\\ln\\left(\\cos\\left(6t\\right)\\right)+C$$", "input": "\\int\\:-\\frac{\\sin\\left(6t\\right)\\left(-60\\sec\\left(6t\\right)\\right)}{6}dt", "steps": [ { "type": "step", "primary": "Take the constant out: $$\\int{a\\cdot{f\\left(x\\right)}dx}=a\\cdot\\int{f\\left(x\\right)dx}$$", "result": "=-\\frac{1}{6}\\cdot\\:\\int\\:\\sin\\left(6t\\right)\\left(-60\\sec\\left(6t\\right)\\right)dt" }, { "type": "interim", "title": "Rewrite using trig identities", "input": "\\int\\:\\sin\\left(6t\\right)\\left(-60\\sec\\left(6t\\right)\\right)dt", "result": "=-\\frac{1}{6}\\cdot\\:\\int\\:-\\frac{60\\sin\\left(6t\\right)}{\\cos\\left(6t\\right)}dt", "steps": [ { "type": "step", "primary": "Use the basic trigonometric identity: $$\\sec\\left(x\\right)=\\frac{1}{\\cos\\left(x\\right)}$$", "result": "=\\int\\:\\sin\\left(6t\\right)\\left(-60\\cdot\\:\\frac{1}{\\cos\\left(6t\\right)}\\right)dt" }, { "type": "interim", "title": "Simplify $$\\sin\\left(6t\\right)\\left(-60\\cdot\\:\\frac{1}{\\cos\\left(6t\\right)}\\right):{\\quad}-\\frac{60\\sin\\left(6t\\right)}{\\cos\\left(6t\\right)}$$", "input": "\\sin\\left(6t\\right)\\left(-60\\cdot\\:\\frac{1}{\\cos\\left(6t\\right)}\\right)", "steps": [ { "type": "step", "primary": "Remove parentheses: $$\\left(-a\\right)=-a$$", "result": "=-\\sin\\left(6t\\right)\\cdot\\:60\\cdot\\:\\frac{1}{\\cos\\left(6t\\right)}" }, { "type": "step", "primary": "Multiply fractions: $$a\\cdot\\frac{b}{c}=\\frac{a\\:\\cdot\\:b}{c}$$", "result": "=-\\frac{1\\cdot\\:\\sin\\left(6t\\right)\\cdot\\:60}{\\cos\\left(6t\\right)}" }, { "type": "step", "primary": "Multiply the numbers: $$1\\cdot\\:60=60$$", "result": "=-\\frac{60\\sin\\left(6t\\right)}{\\cos\\left(6t\\right)}" } ], "meta": { "solvingClass": "Solver", "interimType": "Algebraic Manipulation Simplify Title 1Eq" } }, { "type": "step", "result": "=\\int\\:-\\frac{60\\sin\\left(6t\\right)}{\\cos\\left(6t\\right)}dt" } ], "meta": { "interimType": "Trig Rewrite Using Trig identities 0Eq", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7l7+Hp9GxvB/5I+4/5L7s7/Ho1f5syByYLX5P2O73/2j4JMNHLEeqSQIwGXmmBIh+PosKaRMq/pBPumoBrLj89/lZJuHdgx059G6Z6iwp6k/6DZLE6vHKrQJpnGEY59NTD+ZwthOp2oPXI6jTaq4Gz01OtTMuHZvTePg2+GYbCdMIVCLSxSy8rv0jRguSUmNCZEt3ZXAiqUE0HIXrrrezJJi0cdkgnw2HPjRVpcHMxZbIciYVzjaAolEaNkVONtBBRppTNgMFons9bMkTzIHooA==" } }, { "type": "step", "primary": "Take the constant out: $$\\int{a\\cdot{f\\left(x\\right)}dx}=a\\cdot\\int{f\\left(x\\right)dx}$$", "result": "=-\\frac{1}{6}\\left(-60\\cdot\\:\\int\\:\\frac{\\sin\\left(6t\\right)}{\\cos\\left(6t\\right)}dt\\right)" }, { "type": "interim", "title": "Apply u-substitution", "input": "\\int\\:\\frac{\\sin\\left(6t\\right)}{\\cos\\left(6t\\right)}dt", "steps": [ { "type": "definition", "title": "Integral Substitution definition", "text": "$$\\int\\:f\\left(g\\left(x\\right)\\right)\\cdot\\:g'\\left(x\\right)dx=\\int\\:f\\left(u\\right)du,\\:\\quad\\:u=g\\left(x\\right)$$", "secondary": [ "Substitute: $$u=\\cos\\left(6t\\right)$$" ] }, { "type": "interim", "title": "$$\\frac{du}{dt}=-\\sin\\left(6t\\right)6$$", "input": "\\left(\\cos\\left(6t\\right)\\right)^{\\prime}", "steps": [ { "type": "interim", "title": "Apply the chain rule:$${\\quad}-\\sin\\left(6t\\right)\\left(6t\\right)^{\\prime}$$", "input": "\\left(\\cos\\left(6t\\right)\\right)^{\\prime}", "result": "=-\\sin\\left(6t\\right)\\left(6t\\right)^{\\prime}", "steps": [ { "type": "step", "primary": "Apply the chain rule: $$\\frac{df\\left(u\\right)}{dx}=\\frac{df}{du}\\cdot\\frac{du}{dx}$$", "secondary": [ "$$f=\\cos\\left(u\\right),\\:\\:u=6t$$" ], "result": "=\\left(\\cos\\left(u\\right)\\right)^{^{\\prime}}\\left(6t\\right)^{^{\\prime}}", "meta": { "practiceLink": "/practice/derivatives-practice#area=main&subtopic=Chain%20Rule", "practiceTopic": "Chain Rule" } }, { "type": "interim", "title": "$$\\left(\\cos\\left(u\\right)\\right)^{\\prime}=-\\sin\\left(u\\right)$$", "input": "\\left(\\cos\\left(u\\right)\\right)^{\\prime}", "steps": [ { "type": "step", "primary": "Apply the common derivative: $$\\left(\\cos\\left(u\\right)\\right)^{\\prime}=-\\sin\\left(u\\right)$$", "result": "=-\\sin\\left(u\\right)" } ], "meta": { "solvingClass": "Derivatives", "interimType": "Derivatives", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7aJtZOJKzwzgX3sX8vWzwyLRGYgE/Uo1dnewG4GHneMqXIQHgliMhSOSNsNni19In4/yNG6RtaMeFUKXMVc75z2DpznShoZau34eGycg+7G3mVcoSp6dsHpd9bDcXuJ0pz2gvuHI/drUkZ7NmziNx4SS3daIZHtloJpe/PvtsyNI=" } }, { "type": "step", "result": "=-\\sin\\left(u\\right)\\left(6t\\right)^{^{\\prime}}" }, { "type": "step", "primary": "Substitute back $$u=6t$$", "result": "=-\\sin\\left(6t\\right)\\left(6t\\right)^{^{\\prime}}" } ], "meta": { "interimType": "Derivative Chain Rule 0Eq", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7aJtZOJKzwzgX3sX8vWzwyIu/GYkmDFNPqT12rKBwQ9JJQz2lqSQogu9PoWz88zfnZQ9Z3Siv7iLdHqZDfvh55mmSkC3Mw9EDaBd1JKNjy8RLUkD296vqd81SRk8bq7AlJcj6EQVgLle9yFp8cy8qck3kCh3oevUunZ7/b0qFKBSgKzM+BlIedhng7m5DQQLWtIFBygoY9STUrg+h4aNkjw==" } }, { "type": "interim", "title": "$$\\left(6t\\right)^{\\prime}=6$$", "input": "\\left(6t\\right)^{\\prime}", "steps": [ { "type": "step", "primary": "Take the constant out: $$\\left(a{\\cdot}f\\right)'=a{\\cdot}f'$$", "result": "=6t^{^{\\prime}}" }, { "type": "step", "primary": "Apply the common derivative: $$t^{\\prime}=1$$", "result": "=6\\cdot\\:1" }, { "type": "step", "primary": "Simplify", "result": "=6", "meta": { "solvingClass": "Solver" } } ], "meta": { "solvingClass": "Derivatives", "interimType": "Derivatives", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7zgsQLHKcE4bPMk/tfhJr3MPQlVFV646ejpUuEWqujX2QuIxj9K+Upo9l4tAcwN/gV29r656qFR0DUTLPqu9PtMnS+huczlXBlThLcwNi14o7wEWcvxYk7LAulItRhl3H" } }, { "type": "step", "result": "=-\\sin\\left(6t\\right)\\cdot\\:6" } ], "meta": { "solvingClass": "Derivatives", "interimType": "Derivatives" } }, { "type": "step", "primary": "$$\\quad\\Rightarrow\\:du=-\\sin\\left(6t\\right)6dt$$" }, { "type": "step", "primary": "$$\\quad\\Rightarrow\\:dt=\\left(-\\frac{1}{6\\sin\\left(6t\\right)}\\right)du$$" }, { "type": "step", "result": "=\\int\\:\\frac{\\sin\\left(6t\\right)}{u}\\left(-\\frac{1}{6\\sin\\left(6t\\right)}\\right)du" }, { "type": "interim", "title": "Simplify $$\\frac{\\sin\\left(6t\\right)}{u}\\left(-\\frac{1}{6\\sin\\left(6t\\right)}\\right):{\\quad}-\\frac{1}{6u}$$", "input": "\\frac{\\sin\\left(6t\\right)}{u}\\left(-\\frac{1}{6\\sin\\left(6t\\right)}\\right)", "steps": [ { "type": "step", "primary": "Remove parentheses: $$\\left(-a\\right)=-a$$", "result": "=-\\frac{\\sin\\left(6t\\right)}{u}\\cdot\\:\\frac{1}{6\\sin\\left(6t\\right)}" }, { "type": "step", "primary": "Multiply fractions: $$\\frac{a}{b}\\cdot\\frac{c}{d}=\\frac{a\\:\\cdot\\:c}{b\\:\\cdot\\:d}$$", "result": "=-\\frac{\\sin\\left(6t\\right)\\cdot\\:1}{u\\cdot\\:6\\sin\\left(6t\\right)}" }, { "type": "step", "primary": "Cancel the common factor: $$\\sin\\left(6t\\right)$$", "result": "=-\\frac{1}{u\\cdot\\:6}" } ], "meta": { "solvingClass": "Solver", "interimType": "Algebraic Manipulation Simplify Title 1Eq" } }, { "type": "step", "result": "=\\int\\:-\\frac{1}{6u}du" } ], "meta": { "interimType": "Integral U Substitution 1Eq", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7l7+Hp9GxvB/5I+4/5L7s70pAj3nshv2/cgcf2w7gObzU0lGg8OCCWpWoa+bX9fNNpN4cZPWgnwFqHQUcV4FHsfBLh5j/jJcd1Frv9s/1xSw0pWMfsJc1e/Z0+a/wFZqiXhnWZkvWO3GkAy05vuDu098kl0JLOd5E4HERWWY8WYR6pfF1z6umzUJTJvt+ojYZJI7syIHiVINdMmyoKtK9trcRCHe5WXEh3UwLAL5k2RY=" } }, { "type": "step", "result": "=-\\frac{1}{6}\\left(-60\\cdot\\:\\int\\:-\\frac{1}{6u}du\\right)" }, { "type": "step", "primary": "Take the constant out: $$\\int{a\\cdot{f\\left(x\\right)}dx}=a\\cdot\\int{f\\left(x\\right)dx}$$", "result": "=-\\frac{1}{6}\\left(-60\\left(-\\frac{1}{6}\\cdot\\:\\int\\:\\frac{1}{u}du\\right)\\right)" }, { "type": "step", "primary": "Use the common integral:$$\\quad\\:\\int\\:\\frac{1}{u}du=\\ln\\left(u\\right),\\:$$assuming a complex-valued logarithm", "result": "=-\\frac{1}{6}\\left(-60\\left(-\\frac{1}{6}\\ln\\left(u\\right)\\right)\\right)" }, { "type": "step", "primary": "Substitute back $$u=\\cos\\left(6t\\right)$$", "result": "=-\\frac{1}{6}\\left(-60\\left(-\\frac{1}{6}\\ln\\left(\\cos\\left(6t\\right)\\right)\\right)\\right)" }, { "type": "interim", "title": "Simplify $$-\\frac{1}{6}\\left(-60\\left(-\\frac{1}{6}\\ln\\left(\\cos\\left(6t\\right)\\right)\\right)\\right):{\\quad}-\\frac{5}{3}\\ln\\left(\\cos\\left(6t\\right)\\right)$$", "input": "-\\frac{1}{6}\\left(-60\\left(-\\frac{1}{6}\\ln\\left(\\cos\\left(6t\\right)\\right)\\right)\\right)", "result": "=-\\frac{5}{3}\\ln\\left(\\cos\\left(6t\\right)\\right)", "steps": [ { "type": "step", "primary": "Remove parentheses: $$\\left(-a\\right)=-a,\\:-\\left(-a\\right)=a$$", "result": "=-\\frac{1}{6}\\cdot\\:60\\cdot\\:\\frac{1}{6}\\ln\\left(\\cos\\left(6t\\right)\\right)" }, { "type": "step", "primary": "Multiply fractions: $$a\\cdot\\frac{b}{c}\\cdot\\frac{d}{e}=\\frac{a\\:\\cdot\\:b\\:\\cdot\\:d}{c\\:\\cdot\\:e}$$", "result": "=-\\frac{1\\cdot\\:1\\cdot\\:60}{6\\cdot\\:6}\\ln\\left(\\cos\\left(6t\\right)\\right)" }, { "type": "interim", "title": "$$\\frac{1\\cdot\\:1\\cdot\\:60}{6\\cdot\\:6}=\\frac{5}{3}$$", "input": "\\frac{1\\cdot\\:1\\cdot\\:60}{6\\cdot\\:6}", "steps": [ { "type": "step", "primary": "Multiply the numbers: $$1\\cdot\\:1\\cdot\\:60=60$$", "result": "=\\frac{60}{6\\cdot\\:6}" }, { "type": "step", "primary": "Multiply the numbers: $$6\\cdot\\:6=36$$", "result": "=\\frac{60}{36}" }, { "type": "step", "primary": "Cancel the common factor: $$12$$", "result": "=\\frac{5}{3}" } ], "meta": { "solvingClass": "Solver", "interimType": "Solver", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7CLfSHLR0CGVpdHoWBOzGCowE2URjZARlATUv6zVtxJNE7r4fTGiuAq5JqOECsqeiCUCWbkwGOY7PqKo3U/JLJep+4H7LyhX9URx2zSV8Ceo/y9DKGIPglJ+qMi9xDu2K0Y8qUu7oNXob/DVNHRtUnpJqWSvpKvaIS+CLplmxaYOg9OBfnneqJX8MHqhtbw44V2XjVNEekh8JtG3ZXDlTQQ==" } }, { "type": "step", "result": "=-\\frac{5}{3}\\ln\\left(\\cos\\left(6t\\right)\\right)" } ], "meta": { "solvingClass": "Solver", "interimType": "Generic Simplify Specific 1Eq", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7dEuqhqh+PfYcuFG0/ZQwNDqZekvJjcQK6OkLUxJHCxkpAo1lvc7yWNp4VIEbivA89s43/aG4RqIhR8wn5cy6THm0yklMEFxxRaRLK8x7VKkyB9dQ6271ePBbbMIuwSyP0v0ULx2e3D9Bw5jDhjQWlYEFMST8lDZxn1Yq5HMKVTvaBf/y/iatBPxn+bAoT0bW1++P4VvM3vd7qongLhcLBT8GHcxh/HLhbnEHrfyuvOQtS4B8vIL2NCshVI1KoKTIJLd1ohke2Wgml78++2zI0g==" } }, { "type": "step", "primary": "Add a constant to the solution", "result": "=-\\frac{5}{3}\\ln\\left(\\cos\\left(6t\\right)\\right)+C", "meta": { "title": { "extension": "If $$\\frac{dF\\left(x\\right)}{dx}=f\\left(x\\right)$$ then $$\\int{f\\left(x\\right)}dx=F\\left(x\\right)+C$$" } } } ], "meta": { "solvingClass": "Integrals", "interimType": "Integrals" } }, { "type": "step", "result": "u_{1}=-\\frac{5}{3}\\ln\\left(\\cos\\left(6t\\right)\\right)" }, { "type": "step", "primary": "$$u_{2}=\\int\\:\\frac{y_{1}g\\left(t\\right)}{W\\left(y_{1},\\:y_{2}\\right)}dt$$", "result": "u_{2}=\\int\\:\\frac{\\cos\\left(6t\\right)\\left(-60\\sec\\left(6t\\right)\\right)}{6}dt" }, { "type": "interim", "title": "$$\\int\\:\\frac{\\cos\\left(6t\\right)\\left(-60\\sec\\left(6t\\right)\\right)}{6}dt=-10t+C$$", "input": "\\int\\:\\frac{\\cos\\left(6t\\right)\\left(-60\\sec\\left(6t\\right)\\right)}{6}dt", "steps": [ { "type": "interim", "title": "$$\\frac{\\cos\\left(6t\\right)\\left(-60\\sec\\left(6t\\right)\\right)}{6}=-10$$", "input": "\\frac{\\cos\\left(6t\\right)\\left(-60\\sec\\left(6t\\right)\\right)}{6}", "steps": [ { "type": "step", "primary": "Remove parentheses: $$\\left(-a\\right)=-a$$", "result": "=\\frac{-\\cos\\left(6t\\right)\\cdot\\:60\\sec\\left(6t\\right)}{6}" }, { "type": "step", "primary": "Apply the fraction rule: $$\\frac{-a}{b}=-\\frac{a}{b}$$", "result": "=-\\frac{\\cos\\left(6t\\right)\\cdot\\:60\\sec\\left(6t\\right)}{6}" }, { "type": "step", "primary": "Divide the numbers: $$\\frac{60}{6}=10$$", "result": "=-10\\cos\\left(6t\\right)\\sec\\left(6t\\right)" }, { "type": "interim", "title": "$$\\sec\\left(6t\\right)\\cos\\left(6t\\right)=1$$", "input": "\\sec\\left(6t\\right)\\cos\\left(6t\\right)", "steps": [ { "type": "interim", "title": "Express with sin, cos", "input": "\\sec\\left(6t\\right)\\cos\\left(6t\\right)", "steps": [ { "type": "step", "primary": "Use the basic trigonometric identity: $$\\sec\\left(6t\\right)=\\frac{1}{\\cos\\left(6t\\right)}$$", "result": "=\\frac{1}{\\cos\\left(6t\\right)}\\cos\\left(6t\\right)" }, { "type": "interim", "title": "$$\\frac{1}{\\cos\\left(6t\\right)}\\cos\\left(6t\\right)=1$$", "input": "\\frac{1}{\\cos\\left(6t\\right)}\\cos\\left(6t\\right)", "result": "=1", "steps": [ { "type": "step", "primary": "Multiply fractions: $$a\\cdot\\frac{b}{c}=\\frac{a\\:\\cdot\\:b}{c}$$", "result": "=\\frac{1\\cos\\left(6t\\right)}{\\cos\\left(6t\\right)}" }, { "type": "step", "primary": "Cancel the common factor: $$\\cos\\left(6t\\right)$$", "result": "=1" } ], "meta": { "solvingClass": "Solver", "interimType": "Solver", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s743+Hzh+1NcELvtHIMKV2UMgqTRDXkrDedgMXPjnHlLotOtZYwUjyXhDTsNnn6ElrPGrllHeFjaKLCz4xpIb40UeCBKuYKgaNJ253gLI69U75pEyVJwsO/EEQdwGeaLTMNZInpLv7ge9+QPnPK/GU8Q==" } } ], "meta": { "interimType": "Trig Express Sin Cos 0Eq" } } ], "meta": { "interimType": "N/A" } }, { "type": "step", "result": "=-10\\cdot\\:1" }, { "type": "step", "primary": "Multiply the numbers: $$10\\cdot\\:1=10$$", "result": "=-10" } ], "meta": { "solvingClass": "Solver", "interimType": "Solver", "gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7UBFdZJfM6LtMHjZGPeyr3c101Rb0EKrI1B4fDzRx0T+axcbbZAOSNlm7F86qWQtXzMFYmi1F5Hg/ibpEToVnY8LDiesSbIvTYqz2p2k8mWaFAx1vVBfYA0EqU/MNM02oWyczvjuiETmqRwoz9fEzFEgTNeDaE3f6yTz7Ce+SWdc=" } }, { "type": "step", "result": "=\\int\\:-10dt" }, { "type": "step", "primary": "Integral of a constant: $$\\int{a}dx=ax$$", "result": "=\\left(-10\\right)t" }, { "type": "step", "primary": "Simplify", "result": "=-10t", "meta": { "solvingClass": "Solver" } }, { "type": "step", "primary": "Add a constant to the solution", "result": "=-10t+C", "meta": { "title": { "extension": "If $$\\frac{dF\\left(x\\right)}{dx}=f\\left(x\\right)$$ then $$\\int{f\\left(x\\right)}dx=F\\left(x\\right)+C$$" } } } ], "meta": { "solvingClass": "Integrals", "interimType": "Integrals" } }, { "type": "step", "result": "u_{2}=-10t" }, { "type": "step", "primary": "$$y_{p}=u_{1}y_{1}+u_{2}y_{2}$$", "result": "y_{p}=\\left(-\\frac{5}{3}\\ln\\left(\\cos\\left(6t\\right)\\right)\\right)\\cos\\left(6t\\right)+\\left(-10t\\right)\\sin\\left(6t\\right)" }, { "type": "interim", "title": "Simplify", "input": "\\left(-\\frac{5}{3}\\ln\\left(\\cos\\left(6t\\right)\\right)\\right)\\cos\\left(6t\\right)+\\left(-10t\\right)\\sin\\left(6t\\right)", "result": "y_{p}=-\\frac{5}{3}\\ln\\left(\\cos\\left(6t\\right)\\right)\\cos\\left(6t\\right)-10t\\sin\\left(6t\\right)", "steps": [ { "type": "step", "primary": "Remove parentheses: $$\\left(-a\\right)=-a$$", "result": "=-\\frac{5}{3}\\ln\\left(\\cos\\left(6t\\right)\\right)\\cos\\left(6t\\right)-10t\\sin\\left(6t\\right)" } ], "meta": { "solvingClass": "Solver", "interimType": "Generic Simplify Title 0Eq" } }, { "type": "step", "primary": "A particular solution $$y_{p}$$ to$${\\quad}y^{\\prime\\prime}\\left(t\\right)+36y=-60\\sec\\left(6t\\right){\\quad}$$is:", "result": "y_{p}=-\\frac{5}{3}\\ln\\left(\\cos\\left(6t\\right)\\right)\\cos\\left(6t\\right)-10t\\sin\\left(6t\\right)" } ], "meta": { "interimType": "Generic Find That Satisfies Title 2Eq" } }, { "type": "step", "primary": "The general solution $$y=y_h+y_p$$ is:", "result": "y=c_{1}\\cos\\left(6t\\right)+c_{2}\\sin\\left(6t\\right)-\\frac{5}{3}\\ln\\left(\\cos\\left(6t\\right)\\right)\\cos\\left(6t\\right)-10t\\sin\\left(6t\\right)" } ], "meta": { "interimType": "ODE Solve Linear 0Eq" } }, { "type": "step", "result": "y=c_{1}\\cos\\left(6t\\right)+c_{2}\\sin\\left(6t\\right)-\\frac{5}{3}\\ln\\left(\\cos\\left(6t\\right)\\right)\\cos\\left(6t\\right)-10t\\sin\\left(6t\\right)" } ], "meta": { "solvingClass": "ODE" } }, "plot_output": { "meta": { "plotInfo": { "variable": "t", "plotRequest": "#>#ODE#>#y=c_{1}\\cos(6t)+c_{2}\\sin(6t)-\\frac{5}{3}\\ln(\\cos(6t))\\cos(6t)-10t\\sin(6t)" } } }, "meta": { "showVerify": true } }