{
"query": {
"display": "foci $$y^{2}=-12x$$",
"symbolab_question": "CONIC#foci y^{2}=-12x"
},
"solution": {
"level": "PERFORMED",
"subject": "Geometry",
"topic": "Parabola",
"subTopic": "foci",
"default": "(-3,0)"
},
"steps": {
"type": "interim",
"title": "Parabola focus given $$y^{2}=-12x:{\\quad}\\left(-3,\\:0\\right)$$",
"steps": [
{
"type": "definition",
"title": "Parabola Focus",
"text": "A parabola is the locus of points such that the distance to a point (the focus) equals the distance to a line (the directrix)"
},
{
"type": "definition",
"title": "Parabola standard equation",
"text": "$$4p\\left(x-h\\right)=\\left(y-k\\right)^{2}\\:$$ is the standard equation for a right-left facing parabola with vertex at $$\\left(h,\\:k\\right),\\:$$<br/>and a focal length $$|p|$$"
},
{
"type": "interim",
"title": "Rewrite $$y^{2}=-12x\\:$$in the standard form:$${\\quad}4\\left(-3\\right)\\left(x-0\\right)=\\left(y-0\\right)^{2}$$",
"input": "y^{2}=-12x",
"steps": [
{
"type": "step",
"primary": "Switch sides",
"result": "-12x=y^{2}"
},
{
"type": "step",
"primary": "Factor $$4$$",
"result": "4\\cdot\\:\\frac{-12}{4}x=y^{2}"
},
{
"type": "step",
"primary": "Simplify",
"result": "4\\left(-3\\right)x=y^{2}"
},
{
"type": "step",
"primary": "Rewrite as",
"result": "4\\left(-3\\right)\\left(x-0\\right)=\\left(y-0\\right)^{2}"
}
],
"meta": {
"interimType": "Parabola Canonical Format Title 1Eq",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7aRgRQFW0MqhVT4GbzWEc4k7qsHRxN9bqMsP43ThlkcsWgM/Qnh8bwlZVgLtIW15FQXpHylPs0Rersq/WcBN38o9ZLTbv6820yRhHB5ziAqjzWuLWZ/TGm41cerLey75mp+53YEFIjmIWpl3qnAYzGk3kCh3oevUunZ7/b0qFKBTZZW2tgiEsjlMZIVVWRbS+o9C2jiCFyIh1uTMQAb7OSWkbCg93zvRCzMqKIe6ln76KGM5KjXEoq5HFg4B+mSdM"
}
},
{
"type": "step",
"result": "\\left(h,\\:k\\right)=\\left(0,\\:0\\right),\\:p=-3"
},
{
"type": "step",
"primary": "Parabola is symmetric around the x-axis and so the focus lies a distance $$p$$ from the center $$\\left(0,\\:0\\right)$$ along the x-axis ",
"result": "\\left(0+p,\\:0\\right)"
},
{
"type": "step",
"result": "=\\left(0+\\left(-3\\right),\\:0\\right)"
},
{
"type": "step",
"primary": "Refine",
"result": "\\left(-3,\\:0\\right)"
}
],
"meta": {
"solvingClass": "Parabola"
}
},
"plot_output": {
"meta": {
"plotInfo": {
"variable": "x",
"funcsToDraw": {
"funcs": [
{
"evalFormula": "y=\\sqrt{4(-3)x}+0",
"displayFormula": "4(-3)x=y^{2}",
"attributes": {
"color": "PURPLE",
"lineType": "NORMAL",
"isAsymptote": false
}
},
{
"evalFormula": "y=-\\sqrt{4(-3)x}+0",
"displayFormula": "4(-3)x=y^{2}",
"attributes": {
"color": "PURPLE",
"lineType": "NORMAL",
"isAsymptote": false
}
},
{
"evalFormula": "x=3",
"displayFormula": "x=3",
"attributes": {
"color": "GRAY",
"lineType": "NORMAL",
"labels": [
"\\mathrm{directrix}"
],
"isAsymptote": false
}
}
]
},
"pointsToDraw": {
"pointsLatex": [
"(0,0)",
"(-3,0)"
],
"pointsDecimal": [
{
"fst": 0,
"snd": 0
},
{
"fst": -3,
"snd": 0
}
],
"attributes": [
{
"color": "PURPLE",
"labels": [
"\\mathrm{vertex}"
],
"labelTypes": [
"DEFAULT"
],
"labelColors": [
"PURPLE"
]
},
{
"color": "PURPLE",
"labels": [
"\\mathrm{focus}"
],
"labelTypes": [
"DEFAULT"
],
"labelColors": [
"PURPLE"
]
}
]
},
"functionChanges": [
{
"origFormulaLatex": [],
"finalFormulaLatex": [],
"plotTitle": "4(-3)(x)=y^{2}",
"paramsLatex": [],
"paramsReplacementsLatex": []
}
],
"localBoundingBox": {
"xMin": -33.75,
"xMax": 33.75,
"yMin": -33.75,
"yMax": 33.75
}
},
"showViewLarger": true
}
}
}
Solution
foci
Solution
Solution steps
Rewrite in the standard form:
Parabola is symmetric around the x-axis and so the focus lies a distance from the center along the x-axis
Refine
Graph
Popular Examples
9x^2-y^2-36x-6y+18=09y^2-16x^2=144(x-1)^2+y^2=1foci 16x^2+25y^2=400foci vertices (x^2)/(25)+(y^2)/(16)=1vertices
Frequently Asked Questions (FAQ)
What is the foci y^2=-12x ?
The foci y^2=-12x is (-3,0)