{
"query": {
"display": "vertices $$f\\left(x\\right)=-3x^{2}+18x-8$$",
"symbolab_question": "CONIC#vertices f(x)=-3x^{2}+18x-8"
},
"solution": {
"level": "PERFORMED",
"subject": "Geometry",
"topic": "Parabola",
"subTopic": "vertices",
"default": "\\mathrm{Maximum}\\:(3,19)",
"meta": {
"showVerify": true
}
},
"methods": [
{
"method": "Find vertex using polynomial form",
"query": {
"display": "vertex quadratic $$y=-3x^{2}+18x-8$$",
"symbolab_question": "vertexquadratic y=-3x^{2}+18x-8"
}
},
{
"method": "Find vertex using parabola form",
"query": {
"display": "vertex parabola $$y=-3x^{2}+18x-8$$",
"symbolab_question": "vertexparabola y=-3x^{2}+18x-8"
}
},
{
"method": "Find vertex using vertex form",
"query": {
"display": "vertex form $$y=-3x^{2}+18x-8$$",
"symbolab_question": "vertexform y=-3x^{2}+18x-8"
}
},
{
"method": "Find vertex using averaging the zeros",
"query": {
"display": "vertex zeros $$y=-3x^{2}+18x-8$$",
"symbolab_question": "vertexzeros y=-3x^{2}+18x-8"
}
}
],
"steps": {
"type": "interim",
"title": "Parabola vertex given $$y=-3x^{2}+18x-8:{\\quad}$$Maximum $$\\left(3,\\:19\\right)$$",
"input": "y=-3x^{2}+18x-8",
"steps": [
{
"type": "definition",
"title": "Parabola equation in polynomial form",
"text": "The vertex of an up-down facing parabola of the form $$y=ax^2+bx+c\\:$$is $$x_{v}=-\\frac{b}{2a}$$"
},
{
"type": "step",
"primary": "The parabola parameters are:",
"result": "a=-3,\\:b=18,\\:c=-8"
},
{
"type": "step",
"primary": "$$x_{v}=-\\frac{b}{2a}$$",
"result": "x_{v}=-\\frac{18}{2\\left(-3\\right)}"
},
{
"type": "interim",
"title": "Simplify $$-\\frac{18}{2\\left(-3\\right)}:{\\quad}3$$",
"input": "-\\frac{18}{2\\left(-3\\right)}",
"result": "x_{v}=3",
"steps": [
{
"type": "step",
"primary": "Remove parentheses: $$\\left(-a\\right)=-a$$",
"result": "=-\\frac{18}{-2\\cdot\\:3}"
},
{
"type": "step",
"primary": "Multiply the numbers: $$2\\cdot\\:3=6$$",
"result": "=-\\frac{18}{-6}"
},
{
"type": "step",
"primary": "Apply the fraction rule: $$\\frac{a}{-b}=-\\frac{a}{b}$$",
"result": "=-\\left(-\\frac{18}{6}\\right)"
},
{
"type": "step",
"primary": "Divide the numbers: $$\\frac{18}{6}=3$$",
"result": "=-\\left(-3\\right)"
},
{
"type": "step",
"primary": "Apply rule $$-\\left(-a\\right)=a$$",
"result": "=3"
}
],
"meta": {
"solvingClass": "Solver",
"interimType": "Generic Simplify Specific 1Eq",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7RtxjuGHamb8yp1ORZOVDebM1yKzQWXXYFS09QAKLmt7MwViaLUXkeD+JukROhWdjqqRb86vK1jAPxwJmTBc7jx4pgUWEah0lniZLlD4X0wtSf3pTTy+YYQVrKzFN7mUna2okK4HEtoi0OpViBcfAiQ=="
}
},
{
"type": "interim",
"title": "Plug in $$x_{v}=3\\:$$to find the $$y_{v}\\:$$value",
"input": "y_{v}=-3\\cdot\\:3^{2}+18\\cdot\\:3-8",
"result": "y_{v}=19",
"steps": [
{
"type": "interim",
"title": "Simplify $$-3\\cdot\\:3^{2}+18\\cdot\\:3-8:{\\quad}19$$",
"input": "-3\\cdot\\:3^{2}+18\\cdot\\:3-8",
"result": "y_{v}=19",
"steps": [
{
"type": "interim",
"title": "$$3\\cdot\\:3^{2}=3^{3}$$",
"input": "3\\cdot\\:3^{2}",
"steps": [
{
"type": "step",
"primary": "Apply exponent rule: $$a^b\\cdot\\:a^c=a^{b+c}$$",
"secondary": [
"$$3\\cdot\\:3^{2}=\\:3^{1+2}$$"
],
"result": "=3^{1+2}",
"meta": {
"practiceLink": "/practice/exponent-practice",
"practiceTopic": "Expand FOIL"
}
},
{
"type": "step",
"primary": "Add the numbers: $$1+2=3$$",
"result": "=3^{3}"
}
],
"meta": {
"solvingClass": "Solver",
"interimType": "Solver",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7Hms94GO2lPhP86CRLnF5ZS061ljBSPJeENOw2efoSWsQTQNYsb/dJGjOWnJrejA1/z//r+dXk7h9vxeDCLuZqr/a44LhFnPi3hnaJemt/8jII+mBznc+g6xGnMwA8n4l"
}
},
{
"type": "interim",
"title": "$$18\\cdot\\:3=54$$",
"input": "18\\cdot\\:3",
"steps": [
{
"type": "step",
"primary": "Multiply the numbers: $$18\\cdot\\:3=54$$",
"result": "=54"
}
],
"meta": {
"solvingClass": "Solver",
"interimType": "Solver",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s75iXBtX2/Il5hpgUl9hnoiyAn9lkDfZkicUGkO3EF+IqCgDgxxcrQEo5KrPMPckaifvJ0JoMFys4yEED0JNmYai50wz63FpzuEtXxIb6OKc8="
}
},
{
"type": "step",
"result": "=-3^{3}+54-8"
},
{
"type": "step",
"primary": "Add/Subtract the numbers: $$54-8=46$$",
"result": "=46-3^{3}"
},
{
"type": "step",
"primary": "$$3^{3}=27$$",
"result": "=46-27"
},
{
"type": "step",
"primary": "Subtract the numbers: $$46-27=19$$",
"result": "=19"
}
],
"meta": {
"solvingClass": "Solver",
"interimType": "Generic Simplify Specific 1Eq",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7vOdj406Ua4DRB8rJNsqrZBJFxs0K/E9HR37PaTfY75nehkKrn0era9rz8TlL+x/vVifJ8VdKs2k/AIlbmIu58+9sGZu5A1MXROmEpnxG69pU9CqZ7lZvYEOqUIk+j4vz/ohcON6gZWxWx1UnBonhHQcZVM+afZNRv3WMpbQMT+s="
}
}
],
"meta": {
"interimType": "Plug In Value 2Eq"
}
},
{
"type": "step",
"primary": "Therefore the parabola vertex is",
"result": "\\left(3,\\:19\\right)"
},
{
"type": "step",
"primary": "If $$a<0,\\:$$then the vertex is a maximum value<br/>If $$a>0,\\:$$then the vertex is a minimum value<br/>$$a=-3$$",
"result": "\\mathrm{Maximum}\\:\\left(3,\\:19\\right)"
}
],
"meta": {
"solvingClass": "Parabola"
}
},
"plot_output": {
"meta": {
"plotInfo": {
"variable": "x",
"funcsToDraw": {
"funcs": [
{
"evalFormula": "y=\\frac{(x-3)^{2}}{4(-\\frac{1}{12})}+19",
"displayFormula": "4(-\\frac{1}{12})(y-19)=(x-3)^{2}",
"attributes": {
"color": "PURPLE",
"lineType": "NORMAL",
"isAsymptote": false
}
},
{
"evalFormula": "y=\\frac{229}{12}",
"displayFormula": "y=\\frac{229}{12}",
"attributes": {
"color": "GRAY",
"lineType": "NORMAL",
"labels": [
"\\mathrm{directrix}"
],
"isAsymptote": false
}
}
]
},
"pointsToDraw": {
"pointsLatex": [
"(3,19)",
"(3,\\frac{227}{12})"
],
"pointsDecimal": [
{
"fst": 3,
"snd": 19
},
{
"fst": 3,
"snd": 18.916666666666668
}
],
"attributes": [
{
"color": "PURPLE",
"labels": [
"\\mathrm{vertex}"
],
"labelTypes": [
"DEFAULT"
],
"labelColors": [
"PURPLE"
]
},
{
"color": "PURPLE",
"labels": [
"\\mathrm{focus}"
],
"labelTypes": [
"DEFAULT"
],
"labelColors": [
"PURPLE"
]
}
]
},
"functionChanges": [
{
"origFormulaLatex": [],
"finalFormulaLatex": [],
"plotTitle": "4(-\\frac{1}{12})(y-19)=(x-3)^{2}",
"paramsLatex": [],
"paramsReplacementsLatex": []
}
],
"localBoundingBox": {
"xMin": -12.380952380952381,
"xMax": 15.238095238095239,
"yMin": -5.5238095238095255,
"yMax": 22.095238095238095
}
},
"showViewLarger": true
}
},
"meta": {
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}
}
Solution
vertices
Solution
Solution steps
The parabola parameters are:
Simplify
Plug in to find the value
Therefore the parabola vertex is
If then the vertex is a maximum value
If then the vertex is a minimum value
Graph
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Frequently Asked Questions (FAQ)
What is the vertices f(x)=-3x^2+18x-8 ?
The vertices f(x)=-3x^2+18x-8 is Maximum (3,19)