{
"query": {
"display": "$$\\int\\:-3\\cos\\left(2x\\right)dx$$",
"symbolab_question": "BIG_OPERATOR#\\int -3\\cos(2x)dx"
},
"solution": {
"level": "PERFORMED",
"subject": "Calculus",
"topic": "Integrals",
"subTopic": "Indefinite Integrals",
"default": "-\\frac{3}{2}\\sin(2x)+C",
"meta": {
"showVerify": true
}
},
"steps": {
"type": "interim",
"title": "$$\\int\\:-3\\cos\\left(2x\\right)dx=-\\frac{3}{2}\\sin\\left(2x\\right)+C$$",
"input": "\\int\\:-3\\cos\\left(2x\\right)dx",
"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": "=-3\\cdot\\:\\int\\:\\cos\\left(2x\\right)dx"
},
{
"type": "interim",
"title": "Apply u-substitution",
"input": "\\int\\:\\cos\\left(2x\\right)dx",
"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: $$u=2x$$"
]
},
{
"type": "interim",
"title": "$$\\frac{du}{dx}=2$$",
"input": "\\frac{d}{dx}\\left(2x\\right)",
"steps": [
{
"type": "step",
"primary": "Take the constant out: $$\\left(a{\\cdot}f\\right)'=a{\\cdot}f'$$",
"result": "=2\\frac{dx}{dx}"
},
{
"type": "step",
"primary": "Apply the common derivative: $$\\frac{dx}{dx}=1$$",
"result": "=2\\cdot\\:1"
},
{
"type": "step",
"primary": "Simplify",
"result": "=2",
"meta": {
"solvingClass": "Solver"
}
}
],
"meta": {
"solvingClass": "Derivatives",
"interimType": "Derivatives",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s79Kg+idP5vLVrjUll6eMdYg2sQzwGEAAPyDk8n13Ps8XZGku9zFkxwe1dTH8vycb94wHsFp27x8BxzSfXYcuPllNbbqpyK7JQEZdATEJR51iZ4v02Fm2dNqQJZnxCX4Je"
}
},
{
"type": "step",
"primary": "$$\\quad\\Rightarrow\\:du=2dx$$"
},
{
"type": "step",
"primary": "$$\\quad\\Rightarrow\\:dx=\\frac{1}{2}du$$"
},
{
"type": "step",
"result": "=\\int\\:\\cos\\left(u\\right)\\frac{1}{2}du"
}
],
"meta": {
"interimType": "Integral U Substitution 1Eq",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7l7+Hp9GxvB/5I+4/5L7s74q6JkKmzW6HevVc80KBrFssjvX7KVUO/AeCFSId4S33cZqb2ujmN2FEZC5M/msYIHiX35dQ/h01lIvxamZtt5Pfzl9vMjUAUvB5H3kSKKYo4Ruz4fIbA7DSu1jg0w5EAYEFMST8lDZxn1Yq5HMKVTsGLeMxVl55xMYxEfjKBatulcQUlMOhkqQvF9O8Q8/Z5g=="
}
},
{
"type": "step",
"result": "=-3\\cdot\\:\\int\\:\\cos\\left(u\\right)\\frac{1}{2}du"
},
{
"type": "step",
"primary": "Take the constant out: $$\\int{a\\cdot{f\\left(x\\right)}dx}=a\\cdot\\int{f\\left(x\\right)dx}$$",
"result": "=-3\\cdot\\:\\frac{1}{2}\\cdot\\:\\int\\:\\cos\\left(u\\right)du"
},
{
"type": "step",
"primary": "Use the common integral: $$\\int\\:\\cos\\left(u\\right)du=\\sin\\left(u\\right)$$",
"result": "=-3\\cdot\\:\\frac{1}{2}\\sin\\left(u\\right)"
},
{
"type": "step",
"primary": "Substitute back $$u=2x$$",
"result": "=-3\\cdot\\:\\frac{1}{2}\\sin\\left(2x\\right)"
},
{
"type": "interim",
"title": "Simplify $$-3\\cdot\\:\\frac{1}{2}\\sin\\left(2x\\right):{\\quad}-\\frac{3}{2}\\sin\\left(2x\\right)$$",
"input": "-3\\cdot\\:\\frac{1}{2}\\sin\\left(2x\\right)",
"result": "=-\\frac{3}{2}\\sin\\left(2x\\right)",
"steps": [
{
"type": "step",
"primary": "Multiply fractions: $$a\\cdot\\frac{b}{c}=\\frac{a\\:\\cdot\\:b}{c}$$",
"result": "=-\\frac{1\\cdot\\:3}{2}\\sin\\left(2x\\right)"
},
{
"type": "step",
"primary": "Multiply the numbers: $$1\\cdot\\:3=3$$",
"result": "=-\\frac{3}{2}\\sin\\left(2x\\right)"
}
],
"meta": {
"solvingClass": "Solver",
"interimType": "Generic Simplify Specific 1Eq",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7yKyVpEFPWiPkRzHkKl2/ujqrHbwyajs8pox3tLU3DO4AlilG71elit3w1IBbYN0PlbtMv58phRb2qRbzdA+fvPEFJEVd7mITCLTlFGmw9X/6yHsCG4EHfPjZOAvk9Cx27kAjP76qW66lOUsURwT0nbpeehgYXnnxzR0N9doOX1Ou/JGQuRK/fqUfBKZsGpBREDsLwqmZIQ4ItAd5rnS5TQ=="
}
},
{
"type": "step",
"primary": "Add a constant to the solution",
"result": "=-\\frac{3}{2}\\sin\\left(2x\\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",
"practiceLink": "/practice/integration-practice#area=main&subtopic=Substitution",
"practiceTopic": "Integral Substitution"
}
},
"plot_output": {
"meta": {
"plotInfo": {
"variable": "x",
"plotRequest": "y=-\\frac{3}{2}\\sin(2x)+C"
},
"showViewLarger": true
}
},
"meta": {
"showVerify": true
}
}
Solution
Solution
Solution steps
Take the constant out:
Apply u-substitution
Take the constant out:
Use the common integral:
Substitute back
Simplify
Add a constant to the solution
Graph
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Frequently Asked Questions (FAQ)
What is the integral of-3cos(2x) ?
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