{
"query": {
"display": "area $$2x,\\:x=3$$",
"symbolab_question": "INTEGRAL_APPLICATION#area 2x,x=3"
},
"solution": {
"level": "PERFORMED",
"subject": "Calculus",
"topic": "Integral Applications",
"subTopic": "Area under the curve",
"default": "9"
},
"steps": {
"type": "interim",
"title": "The area between the curves $$f\\left(x\\right)=2x\\:$$and $$x=3:{\\quad}9$$",
"steps": [
{
"type": "definition",
"title": "Area under a curve definition",
"text": "The area under a curve is the area between a curve $$f\\left(x\\right)\\:$$and the x-axis on an interval $$[a,\\:b]\\:$$given by<br/>$$A=\\int_{a}^{b}|f\\left(x\\right)|dx$$"
},
{
"type": "interim",
"title": "Apply the area formula:$${\\quad}\\int_{0}^{3}2\\left|x\\right|dx$$",
"steps": [
{
"type": "step",
"primary": "$$f\\left(x\\right)=2x$$"
},
{
"type": "interim",
"title": "Find intersection points:$${\\quad}x=0$$",
"steps": [
{
"type": "step",
"primary": "To find the intersection points solve $$f\\left(x\\right)=0$$",
"result": "2x=0"
},
{
"type": "interim",
"title": "$$2x=0{\\quad:\\quad}x=0$$",
"input": "2x=0",
"result": "x=0",
"steps": [
{
"type": "interim",
"title": "Divide both sides by $$2$$",
"input": "2x=0",
"result": "x=0",
"steps": [
{
"type": "step",
"primary": "Divide both sides by $$2$$",
"result": "\\frac{2x}{2}=\\frac{0}{2}"
},
{
"type": "step",
"primary": "Simplify",
"result": "x=0"
}
],
"meta": {
"interimType": "Divide Both Sides Specific 1Eq",
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}
}
],
"meta": {
"solvingClass": "Equations",
"interimType": "Equations"
}
}
],
"meta": {
"interimType": "Find Intersection Title 0Eq"
}
},
{
"type": "step",
"primary": "Therefore",
"secondary": [
"$$a=0,\\:b=3$$"
]
},
{
"type": "step",
"result": "=\\int_{0}^{3}\\left|2x\\right|dx"
},
{
"type": "step",
"primary": "Simplify"
},
{
"type": "step",
"result": "=\\int_{0}^{3}2\\left|x\\right|dx"
}
],
"meta": {
"interimType": "Apply Area Formula 0Eq"
}
},
{
"type": "interim",
"title": "Solve $$\\int_{0}^{3}2\\left|x\\right|dx:{\\quad}9$$",
"input": "\\int_{0}^{3}2\\left|x\\right|dx",
"steps": [
{
"type": "interim",
"title": "Eliminate Absolutes",
"input": "\\int_{0}^{3}2\\left|x\\right|dx",
"result": "=\\int_{0}^{3}2xdx",
"steps": [
{
"type": "step",
"primary": "Find the equivalent expressions to $$2\\left|x\\right|$$ at $$0\\le\\:x\\le\\:3$$ without the absolutes"
},
{
"type": "step",
"primary": "$$0\\le\\:x\\le\\:3:{\\quad}2x$$"
},
{
"type": "step",
"result": "=\\int_{0}^{3}2xdx"
}
],
"meta": {
"interimType": "Eliminate Absolutes Integral 2Eq"
}
},
{
"type": "step",
"primary": "Take the constant out: $$\\int{a\\cdot{f\\left(x\\right)}dx}=a\\cdot\\int{f\\left(x\\right)dx}$$",
"result": "=2\\cdot\\:\\int_{0}^{3}xdx"
},
{
"type": "interim",
"title": "Apply the Power Rule",
"input": "\\int_{0}^{3}xdx",
"result": "=2[\\frac{x^{2}}{2}]_{0}^{3}",
"steps": [
{
"type": "step",
"primary": "Apply the Power Rule: $$\\int{x^{a}}dx=\\frac{x^{a+1}}{a+1},\\:\\quad\\:a\\neq{-1}$$",
"result": "=[\\frac{x^{1+1}}{1+1}]_{0}^{3}"
},
{
"type": "interim",
"title": "Simplify $$\\frac{x^{1+1}}{1+1}:{\\quad}\\frac{x^{2}}{2}$$",
"input": "\\frac{x^{1+1}}{1+1}",
"steps": [
{
"type": "step",
"primary": "Add the numbers: $$1+1=2$$",
"result": "=\\frac{x^{2}}{2}"
}
],
"meta": {
"solvingClass": "Solver",
"interimType": "Algebraic Manipulation Simplify Title 1Eq"
}
},
{
"type": "step",
"result": "=[\\frac{x^{2}}{2}]_{0}^{3}"
}
],
"meta": {
"interimType": "Power Rule Top 0Eq",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7l7+Hp9GxvB/5I+4/5L7s73eIza12x517zqyy2AdD8WwsjvX7KVUO/AeCFSId4S33HipIftvBYl8MvlbM/MS0IniX35dQ/h01lIvxamZtt5P0OFtj1jyjvPrkcLqztccOZ4EqGUH6luvzhLyP4MrprdbA+zX4bD3u3gx65o2NJhN+u9S1UanyCrDStYeLlcNDOFynCe2Jk2u4EAkbH+yVgg=="
}
},
{
"type": "interim",
"title": "Compute the boundaries:$${\\quad}\\frac{9}{2}$$",
"input": "[\\frac{x^{2}}{2}]_{0}^{3}",
"steps": [
{
"type": "step",
"primary": "$$\\int_{a}^{b}{f\\left(x\\right)dx}=F\\left(b\\right)-F\\left(a\\right)=\\lim_{x\\to\\:b-}\\left(F\\left(x\\right)\\right)-\\lim_{x\\to\\:a+}\\left(F\\left(x\\right)\\right)$$"
},
{
"type": "interim",
"title": "$$\\lim_{x\\to\\:0+}\\left(\\frac{x^{2}}{2}\\right)=0$$",
"input": "\\lim_{x\\to\\:0+}\\left(\\frac{x^{2}}{2}\\right)",
"steps": [
{
"type": "step",
"primary": "Plug in the value $$x=0$$",
"result": "=\\frac{0^{2}}{2}",
"meta": {
"title": {
"extension": "Limit properties - if the limit of f(x), and g(x) exists, then:<br/>$$\\bullet\\quad\\lim_{x\\to\\:a}\\left(x\\right)=a$$<br/>$$\\bullet\\quad\\lim_{x\\to{a}}[c\\cdot{f\\left(x\\right)}]=c\\cdot\\lim_{x\\to{a}}{f\\left(x\\right)}$$<br/>$$\\bullet\\quad\\lim_{x\\to{a}}[\\left(f\\left(x\\right)\\right)^c]=\\left(\\lim_{x\\to{a}}{f\\left(x\\right)}\\right)^c$$<br/>$$\\bullet\\quad\\lim_{x\\to{a}}[f\\left(x\\right)\\pm{g\\left(x\\right)}]=\\lim_{x\\to{a}}{f\\left(x\\right)}\\pm\\lim_{x\\to{a}}{g\\left(x\\right)}$$<br/>$$\\bullet\\quad\\lim_{x\\to{a}}[f\\left(x\\right)\\cdot{g\\left(x\\right)}]=\\lim_{x\\to{a}}{f\\left(x\\right)}\\cdot\\lim_{x\\to{a}}{g\\left(x\\right)}$$<br/>$$\\bullet\\quad\\lim_{x\\to{a}}\\left(\\frac{f\\left(x\\right)}{g\\left(x\\right)}\\right)=\\frac{\\lim_{x\\to{a}}{f\\left(x\\right)}}{\\lim_{x\\to{a}}{g\\left(x\\right)}},\\:$$where $$\\lim_{x\\to{a}}g\\left(x\\right)\\neq0$$"
}
}
},
{
"type": "interim",
"title": "Simplify $$\\frac{0^{2}}{2}:{\\quad}0$$",
"input": "\\frac{0^{2}}{2}",
"result": "=0",
"steps": [
{
"type": "step",
"primary": "Apply rule $$0^{a}=0$$",
"secondary": [
"$$0^{2}=0$$"
],
"result": "=\\frac{0}{2}"
},
{
"type": "step",
"primary": "Apply rule $$\\frac{0}{a}=0,\\:a\\ne\\:0$$",
"result": "=0"
}
],
"meta": {
"solvingClass": "Solver",
"interimType": "Generic Simplify Specific 1Eq",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7nteUyMJWMp4mm/uXtkFpCVnyYRz18HvB+rp63mPitc8E5aqGN/sLZfeoFZRwtGLqP8vQyhiD4JSfqjIvcQ7timkSOxgqdB0M/sw8Nt2sXXR3DTZYr1PJ9/OYrvIJiwrr+i0Ux3lprvX50CFfl5rrAQ=="
}
}
],
"meta": {
"solvingClass": "Limits",
"interimType": "Limits"
}
},
{
"type": "interim",
"title": "$$\\lim_{x\\to\\:3-}\\left(\\frac{x^{2}}{2}\\right)=\\frac{9}{2}$$",
"input": "\\lim_{x\\to\\:3-}\\left(\\frac{x^{2}}{2}\\right)",
"steps": [
{
"type": "step",
"primary": "Plug in the value $$x=3$$",
"result": "=\\frac{3^{2}}{2}",
"meta": {
"title": {
"extension": "Limit properties - if the limit of f(x), and g(x) exists, then:<br/>$$\\bullet\\quad\\lim_{x\\to\\:a}\\left(x\\right)=a$$<br/>$$\\bullet\\quad\\lim_{x\\to{a}}[c\\cdot{f\\left(x\\right)}]=c\\cdot\\lim_{x\\to{a}}{f\\left(x\\right)}$$<br/>$$\\bullet\\quad\\lim_{x\\to{a}}[\\left(f\\left(x\\right)\\right)^c]=\\left(\\lim_{x\\to{a}}{f\\left(x\\right)}\\right)^c$$<br/>$$\\bullet\\quad\\lim_{x\\to{a}}[f\\left(x\\right)\\pm{g\\left(x\\right)}]=\\lim_{x\\to{a}}{f\\left(x\\right)}\\pm\\lim_{x\\to{a}}{g\\left(x\\right)}$$<br/>$$\\bullet\\quad\\lim_{x\\to{a}}[f\\left(x\\right)\\cdot{g\\left(x\\right)}]=\\lim_{x\\to{a}}{f\\left(x\\right)}\\cdot\\lim_{x\\to{a}}{g\\left(x\\right)}$$<br/>$$\\bullet\\quad\\lim_{x\\to{a}}\\left(\\frac{f\\left(x\\right)}{g\\left(x\\right)}\\right)=\\frac{\\lim_{x\\to{a}}{f\\left(x\\right)}}{\\lim_{x\\to{a}}{g\\left(x\\right)}},\\:$$where $$\\lim_{x\\to{a}}g\\left(x\\right)\\neq0$$"
}
}
},
{
"type": "step",
"primary": "Simplify",
"result": "=\\frac{9}{2}",
"meta": {
"solvingClass": "Solver"
}
}
],
"meta": {
"solvingClass": "Limits",
"interimType": "Limits"
}
},
{
"type": "step",
"result": "=\\frac{9}{2}-0"
},
{
"type": "step",
"primary": "Simplify",
"result": "=\\frac{9}{2}",
"meta": {
"solvingClass": "Solver"
}
}
],
"meta": {
"interimType": "Integral Definite Limit Boundaries 0Eq",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7l7+Hp9GxvB/5I+4/5L7s7wSe6QRBX4py1NvBE779HsmMzLE9R3ZOJUe+Rh6pK1ptj1aPKxxYypVIRLf3NPD6Vh//vWQprcSRFtsjNJQHkmsDqM/FZp+k6cBZGeSeUXb0/z//r+dXk7h9vxeDCLuZqlP7XdP66vn2lDIgOgst4mRdapHA9w5BUr5XcUy5iXqQialcV/dI5TH4fXyp+ncwuA=="
}
},
{
"type": "step",
"result": "=2\\cdot\\:\\frac{9}{2}"
},
{
"type": "step",
"primary": "Simplify",
"result": "=9"
}
],
"meta": {
"solvingClass": "Integrals",
"interimType": "Generic Solve Title 1Eq"
}
},
{
"type": "step",
"primary": "The area is:",
"result": "=9"
}
]
},
"plot_output": {
"meta": {
"plotInfo": {
"variable": "x",
"plotRequest": "yes"
},
"showViewLarger": true
}
}
}
Solution
area
Solution
Solution steps
Apply the area formula:
Solve
The area is:
Graph
Popular Examples
f^{''}(x)=f(x)(dy)/(dx)+2y=7,y(0)=1integral of (x^2-2)sqrt(x)integral of (4+4x)/(1+x^2)f(x)=(2x+1)/(x^2+2)
Frequently Asked Questions (FAQ)
What is area 2x,x=3 ?
The answer to area 2x,x=3 is 9