{
"query": {
"display": "critical points $$-5x^{4}-x^{3}+2x^{2}$$",
"symbolab_question": "FUNCTION#critical -5x^{4}-x^{3}+2x^{2}"
},
"solution": {
"level": "PERFORMED",
"subject": "Functions & Graphing",
"topic": "Functions",
"subTopic": "critical",
"default": "x=\\frac{-3-\\sqrt{329}}{40},x=0,x=\\frac{-3+\\sqrt{329}}{40}"
},
"steps": {
"type": "interim",
"title": "Critical Points of $$-5x^{4}-x^{3}+2x^{2}:{\\quad}x=\\frac{-3-\\sqrt{329}}{40},\\:x=0,\\:x=\\frac{-3+\\sqrt{329}}{40}$$",
"input": "-5x^{4}-x^{3}+2x^{2}",
"steps": [
{
"type": "definition",
"title": "Critical point definition",
"text": "Critical points are points where the function is defined and its derivative is zero or undefined"
},
{
"type": "interim",
"title": "Find where $$f^{\\prime}\\left(x\\right)$$ is equal to zero or undefined",
"input": "-5x^{4}-x^{3}+2x^{2}",
"result": "x=\\frac{-3-\\sqrt{329}}{40},\\:x=0,\\:x=\\frac{-3+\\sqrt{329}}{40}",
"steps": [
{
"type": "interim",
"title": "$$f^{\\prime}\\left(x\\right)=-20x^{3}-3x^{2}+4x$$",
"input": "\\frac{d}{dx}\\left(-5x^{4}-x^{3}+2x^{2}\\right)",
"steps": [
{
"type": "step",
"primary": "Apply the Sum/Difference Rule: $$\\left(f{\\pm}g\\right)'=f'{\\pm}g'$$",
"result": "=-\\frac{d}{dx}\\left(5x^{4}\\right)-\\frac{d}{dx}\\left(x^{3}\\right)+\\frac{d}{dx}\\left(2x^{2}\\right)"
},
{
"type": "interim",
"title": "$$\\frac{d}{dx}\\left(5x^{4}\\right)=20x^{3}$$",
"input": "\\frac{d}{dx}\\left(5x^{4}\\right)",
"steps": [
{
"type": "step",
"primary": "Take the constant out: $$\\left(a{\\cdot}f\\right)'=a{\\cdot}f'$$",
"result": "=5\\frac{d}{dx}\\left(x^{4}\\right)"
},
{
"type": "step",
"primary": "Apply the Power Rule: $$\\frac{d}{dx}\\left(x^a\\right)=a{\\cdot}x^{a-1}$$",
"result": "=5\\cdot\\:4x^{4-1}",
"meta": {
"practiceLink": "/practice/derivatives-practice#area=main&subtopic=Power%20Rule",
"practiceTopic": "Power Rule"
}
},
{
"type": "step",
"primary": "Simplify",
"result": "=20x^{3}",
"meta": {
"solvingClass": "Solver"
}
}
],
"meta": {
"solvingClass": "Derivatives",
"interimType": "Derivatives",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s79Kg+idP5vLVrjUll6eMdYuaIWboyJjcmGa7VgP571ZaTdaV09PMxEKZ9FieghTFwmvxRL4hmKP9Y2xjGkQoL9WYYnHLVfzWgXhHqK+R1GFq5QV7agSZLIzF7D9vX0CHvHaMJZNAfxRwFkO2+yrS2/bCI2sSeA74029n2yo277ZU="
}
},
{
"type": "interim",
"title": "$$\\frac{d}{dx}\\left(x^{3}\\right)=3x^{2}$$",
"input": "\\frac{d}{dx}\\left(x^{3}\\right)",
"steps": [
{
"type": "step",
"primary": "Apply the Power Rule: $$\\frac{d}{dx}\\left(x^a\\right)=a{\\cdot}x^{a-1}$$",
"result": "=3x^{3-1}",
"meta": {
"practiceLink": "/practice/derivatives-practice#area=main&subtopic=Power%20Rule",
"practiceTopic": "Power Rule"
}
},
{
"type": "step",
"primary": "Simplify",
"result": "=3x^{2}",
"meta": {
"solvingClass": "Solver"
}
}
],
"meta": {
"solvingClass": "Derivatives",
"interimType": "Derivatives",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s79Kg+idP5vLVrjUll6eMdYtb6j95rHG7YtZ73Xx2qCjqk3hxk9aCfAWodBRxXgUexf7nh0v5ML3fMP9GgRVbRX/8//6/nV5O4fb8Xgwi7maqO95Is7YBdcRqXmTH8euc2MRY7LLv3QukQErzdJ9wdtQ=="
}
},
{
"type": "interim",
"title": "$$\\frac{d}{dx}\\left(2x^{2}\\right)=4x$$",
"input": "\\frac{d}{dx}\\left(2x^{2}\\right)",
"steps": [
{
"type": "step",
"primary": "Take the constant out: $$\\left(a{\\cdot}f\\right)'=a{\\cdot}f'$$",
"result": "=2\\frac{d}{dx}\\left(x^{2}\\right)"
},
{
"type": "step",
"primary": "Apply the Power Rule: $$\\frac{d}{dx}\\left(x^a\\right)=a{\\cdot}x^{a-1}$$",
"result": "=2\\cdot\\:2x^{2-1}",
"meta": {
"practiceLink": "/practice/derivatives-practice#area=main&subtopic=Power%20Rule",
"practiceTopic": "Power Rule"
}
},
{
"type": "step",
"primary": "Simplify",
"result": "=4x",
"meta": {
"solvingClass": "Solver"
}
}
],
"meta": {
"solvingClass": "Derivatives",
"interimType": "Derivatives",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s79Kg+idP5vLVrjUll6eMdYgEShBvy1snibnAN3NvB1a2TdaV09PMxEKZ9FieghTFwHBO3D9VaGp1eOVvjTiCiEaN6Hv6MoTMtvtU0IQwXdn+XNwOQ43NHE8cpERrPgoqpfTZuddhTh3r/FmyVu4x1Bw=="
}
},
{
"type": "step",
"result": "=-20x^{3}-3x^{2}+4x"
}
],
"meta": {
"solvingClass": "Derivatives",
"interimType": "Derivatives"
}
},
{
"type": "interim",
"title": "Solve $$-20x^{3}-3x^{2}+4x=0:{\\quad}x=0,\\:x=\\frac{-3+\\sqrt{329}}{40},\\:x=\\frac{-3-\\sqrt{329}}{40}$$",
"input": "-20x^{3}-3x^{2}+4x=0",
"steps": [
{
"type": "interim",
"title": "Factor $$-20x^{3}-3x^{2}+4x:{\\quad}-x\\left(20x^{2}+3x-4\\right)$$",
"input": "-20x^{3}-3x^{2}+4x",
"steps": [
{
"type": "step",
"primary": "Apply exponent rule: $$a^{b+c}=a^{b}a^{c}$$",
"secondary": [
"$$x^{2}=xx$$",
"$$x^{3}=x^{2}x$$"
],
"result": "=-20x^{2}x-3xx+4x",
"meta": {
"practiceLink": "/practice/exponent-practice",
"practiceTopic": "Expand FOIL"
}
},
{
"type": "step",
"primary": "Factor out common term $$-x$$",
"result": "=-x\\left(20x^{2}+3x-4\\right)",
"meta": {
"practiceLink": "/practice/factoring-practice",
"practiceTopic": "Factoring"
}
}
],
"meta": {
"solvingClass": "Solver",
"interimType": "Generic Factor Specific 1Eq"
}
},
{
"type": "step",
"result": "-x\\left(20x^{2}+3x-4\\right)=0"
},
{
"type": "step",
"primary": "Using the Zero Factor Principle:$$\\quad$$ If $$ab=0\\:$$then $$a=0\\:$$or $$b=0$$",
"result": "x=0\\lor\\:20x^{2}+3x-4=0"
},
{
"type": "interim",
"title": "Solve $$20x^{2}+3x-4=0:{\\quad}x=\\frac{-3+\\sqrt{329}}{40},\\:x=\\frac{-3-\\sqrt{329}}{40}$$",
"input": "20x^{2}+3x-4=0",
"steps": [
{
"type": "interim",
"title": "Solve with the quadratic formula",
"input": "20x^{2}+3x-4=0",
"result": "{x}_{1,\\:2}=\\frac{-3\\pm\\:\\sqrt{3^{2}-4\\cdot\\:20\\left(-4\\right)}}{2\\cdot\\:20}",
"steps": [
{
"type": "definition",
"title": "Quadratic Equation Formula:",
"text": "For a quadratic equation of the form $$ax^2+bx+c=0$$ the solutions are <br/>$${\\quad}x_{1,\\:2}=\\frac{-b\\pm\\sqrt{b^2-4ac}}{2a}$$"
},
{
"type": "step",
"primary": "For $${\\quad}a=20,\\:b=3,\\:c=-4$$",
"result": "{x}_{1,\\:2}=\\frac{-3\\pm\\:\\sqrt{3^{2}-4\\cdot\\:20\\left(-4\\right)}}{2\\cdot\\:20}"
}
],
"meta": {
"interimType": "Solving The Quadratic Equation With Quadratic Formula Definition 0Eq",
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}
},
{
"type": "interim",
"title": "$$\\sqrt{3^{2}-4\\cdot\\:20\\left(-4\\right)}=\\sqrt{329}$$",
"input": "\\sqrt{3^{2}-4\\cdot\\:20\\left(-4\\right)}",
"result": "{x}_{1,\\:2}=\\frac{-3\\pm\\:\\sqrt{329}}{2\\cdot\\:20}",
"steps": [
{
"type": "step",
"primary": "Apply rule $$-\\left(-a\\right)=a$$",
"result": "=\\sqrt{3^{2}+4\\cdot\\:20\\cdot\\:4}"
},
{
"type": "step",
"primary": "Multiply the numbers: $$4\\cdot\\:20\\cdot\\:4=320$$",
"result": "=\\sqrt{3^{2}+320}"
},
{
"type": "step",
"primary": "$$3^{2}=9$$",
"result": "=\\sqrt{9+320}"
},
{
"type": "step",
"primary": "Add the numbers: $$9+320=329$$",
"result": "=\\sqrt{329}"
}
],
"meta": {
"solvingClass": "Solver",
"interimType": "Solver",
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}
},
{
"type": "step",
"primary": "Separate the solutions",
"result": "{x}_{1}=\\frac{-3+\\sqrt{329}}{2\\cdot\\:20},\\:{x}_{2}=\\frac{-3-\\sqrt{329}}{2\\cdot\\:20}"
},
{
"type": "interim",
"title": "$$x=\\frac{-3+\\sqrt{329}}{2\\cdot\\:20}:{\\quad}\\frac{-3+\\sqrt{329}}{40}$$",
"input": "\\frac{-3+\\sqrt{329}}{2\\cdot\\:20}",
"steps": [
{
"type": "step",
"primary": "Multiply the numbers: $$2\\cdot\\:20=40$$",
"result": "=\\frac{-3+\\sqrt{329}}{40}"
}
],
"meta": {
"solvingClass": "Solver",
"interimType": "Solver",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7S06bDB+MJbrOisU4Z6oFiPrPr56hX/hyqeC/mCQ+Z3/GvPSRcA2I0vLd3rOOIoYLzMFYmi1F5Hg/ibpEToVnY47XFRivRbGxBrjjS1604EFYa3z3g47AsvY0DWUM9WZvFg2QliWVtdiykO19PgU04ugF6XXBFJVDwyH+r/dxdOdNyFzAENZzyb6r73kF0RG1vzIPeEtDfcHv/z8uls8Teg=="
}
},
{
"type": "interim",
"title": "$$x=\\frac{-3-\\sqrt{329}}{2\\cdot\\:20}:{\\quad}\\frac{-3-\\sqrt{329}}{40}$$",
"input": "\\frac{-3-\\sqrt{329}}{2\\cdot\\:20}",
"steps": [
{
"type": "step",
"primary": "Multiply the numbers: $$2\\cdot\\:20=40$$",
"result": "=\\frac{-3-\\sqrt{329}}{40}"
}
],
"meta": {
"solvingClass": "Solver",
"interimType": "Solver",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7QCrI66+7EgSAvN8Xk/GTa/rPr56hX/hyqeC/mCQ+Z3/GvPSRcA2I0vLd3rOOIoYLzMFYmi1F5Hg/ibpEToVnY2jwQPRX2uAFlSqX37lE/cxYa3z3g47AsvY0DWUM9WZvFg2QliWVtdiykO19PgU04s/Yz1uFeesIaVuTylHIyGZNyFzAENZzyb6r73kF0RG1vzIPeEtDfcHv/z8uls8Teg=="
}
},
{
"type": "step",
"primary": "The solutions to the quadratic equation are:",
"result": "x=\\frac{-3+\\sqrt{329}}{40},\\:x=\\frac{-3-\\sqrt{329}}{40}"
}
],
"meta": {
"solvingClass": "Equations",
"interimType": "Generic Solve Title 1Eq"
}
},
{
"type": "step",
"primary": "The solutions are",
"result": "x=0,\\:x=\\frac{-3+\\sqrt{329}}{40},\\:x=\\frac{-3-\\sqrt{329}}{40}"
}
],
"meta": {
"solvingClass": "Equations",
"interimType": "Generic Solve Title 1Eq"
}
},
{
"type": "step",
"result": "x=\\frac{-3-\\sqrt{329}}{40},\\:x=0,\\:x=\\frac{-3+\\sqrt{329}}{40}"
}
],
"meta": {
"interimType": "Explore Function Slope Zero 1Eq",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7owSbZQBVuOtvRJx3LSI/x3l5erYtKTbOfqVrkQIvh85/dr08XsHmtWtDmXL7M/rr7WQg0UsQt1aSg4OK5ATVfCyEl/RW3NF9wWEPfaKFEE8myshBylEgFF4wsaY+xS5tVbHT1tAXn5Bq9/WY6M4/IqN6Hv6MoTMtvtU0IQwXdn/tcZ/ECY+sBUB+A6V/carltrVtPXzKGAb2BNfFdo/SbhMgHIwbQPRHPbacB7yleDMskHVr1WUkkoRbopLNBoA6i1D0ijqMBRGRlOwoJTKotg=="
}
},
{
"type": "step",
"primary": "Identify critical points not in $$f\\left(x\\right)$$ domain"
},
{
"type": "interim",
"title": "Domain of $$-5x^{4}-x^{3}+2x^{2}\\::{\\quad}-\\infty\\:<x<\\infty\\:$$",
"steps": [
{
"type": "definition",
"title": "Domain definition",
"text": "The domain of a function is the set of input or argument values for which the function is real and defined"
},
{
"type": "step",
"primary": "The function has no undefined points nor domain constraints. Therefore, the domain is",
"result": "-\\infty\\:<x<\\infty\\:"
}
],
"meta": {
"solvingClass": "Function Domain",
"interimType": "Function Domain Top 1Eq"
}
},
{
"type": "step",
"primary": "All critical points are in domain",
"result": "x=\\frac{-3-\\sqrt{329}}{40},\\:x=0,\\:x=\\frac{-3+\\sqrt{329}}{40}"
}
],
"meta": {
"solvingClass": "Function Critical"
}
},
"plot_output": {
"meta": {
"plotInfo": {
"variable": "x",
"plotRequest": "-5x^{4}-x^{3}+2x^{2}"
},
"showViewLarger": true
}
}
}
Solution
critical points
Solution
Solution steps
Find where is equal to zero or undefined
Identify critical points not in domain
Domain of
All critical points are in domain
Graph
Popular Examples
domain of f(x)=x-1/18domain inverse of f(x)= 1/(x+12)inverse inverse of f(x)= 1/3 x-3inverse domain of (5x)/(x^2-3x-4)domain range of ((2sqrt(x)+x)^2)/(5+xsqrt(x))range
Frequently Asked Questions (FAQ)
What is the critical-5x^4-x^3+2x^2 ?
The critical-5x^4-x^3+2x^2 is x=(-3-sqrt(329))/(40),x=0,x=(-3+sqrt(329))/(40)