{
"query": {
"display": "domain $$\\frac{x+9}{x^{2}-9}$$",
"symbolab_question": "FUNCTION#domain \\frac{x+9}{x^{2}-9}"
},
"solution": {
"level": "PERFORMED",
"subject": "Functions & Graphing",
"topic": "Functions",
"subTopic": "domain",
"default": "x<-3\\lor -3<x<3\\lor x>3",
"interval": "(-\\infty ,-3)\\cup (-3,3)\\cup (3,\\infty )",
"meta": {
"showVerify": true
}
},
"steps": {
"type": "interim",
"title": "Domain of $$\\frac{x+9}{x^{2}-9}\\::{\\quad}x<-3\\lor\\:-3<x<3\\lor\\:x>3$$",
"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": "interim",
"title": "Find undefined (singularity) points:$${\\quad}x=3,\\:x=-3$$",
"input": "\\frac{x+9}{x^{2}-9}",
"steps": [
{
"type": "step",
"primary": "Take the denominator(s) of $$\\frac{x+9}{x^{2}-9}$$ and compare to zero"
},
{
"type": "interim",
"title": "Solve $$x^{2}-9=0:{\\quad}x=3,\\:x=-3$$",
"input": "x^{2}-9=0",
"steps": [
{
"type": "interim",
"title": "Move $$9\\:$$to the right side",
"input": "x^{2}-9=0",
"result": "x^{2}=9",
"steps": [
{
"type": "step",
"primary": "Add $$9$$ to both sides",
"result": "x^{2}-9+9=0+9"
},
{
"type": "step",
"primary": "Simplify",
"result": "x^{2}=9"
}
],
"meta": {
"interimType": "Move to the Right Title 1Eq",
"gptData": "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"
}
},
{
"type": "step",
"primary": "For $$x^{2}=f\\left(a\\right)$$ the solutions are $$x=\\sqrt{f\\left(a\\right)},\\:\\:-\\sqrt{f\\left(a\\right)}$$"
},
{
"type": "step",
"result": "x=\\sqrt{9},\\:x=-\\sqrt{9}"
},
{
"type": "interim",
"title": "$$\\sqrt{9}=3$$",
"input": "\\sqrt{9}",
"steps": [
{
"type": "step",
"primary": "Factor the number: $$9=3^{2}$$",
"result": "=\\sqrt{3^{2}}"
},
{
"type": "step",
"primary": "Apply radical rule: $$\\sqrt{a^2}=a,\\:\\quad\\:a\\ge0$$",
"secondary": [
"$$\\sqrt{3^{2}}=3$$"
],
"result": "=3"
}
],
"meta": {
"solvingClass": "Solver2",
"interimType": "Solver2",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s74zYoh2RHt5bF5LAil06rQ913jtrSFDx+UNsawjlOjV0Fuo8niSX4SUBqNT4QFNxbcubCnYZOJ5L8/2gsdymw1KIDQ0pFG0qBgUJZZplUxb0="
}
},
{
"type": "interim",
"title": "$$-\\sqrt{9}=-3$$",
"input": "-\\sqrt{9}",
"steps": [
{
"type": "step",
"primary": "Factor the number: $$9=3^{2}$$",
"result": "=-\\sqrt{3^{2}}"
},
{
"type": "step",
"primary": "Apply radical rule: $$\\sqrt{a^2}=a,\\:\\quad\\:a\\ge0$$",
"secondary": [
"$$\\sqrt{3^{2}}=-3$$"
],
"result": "=-3"
}
],
"meta": {
"solvingClass": "Solver2",
"interimType": "Solver2",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7l9NogLgG1Z80hBQjGI22siAn9lkDfZkicUGkO3EF+Ir6E5Lqm+d+IsRw+A/8SCikMHIu6EZfZrJ7HpyNTqg74jkiBatsWcqNKMJJIDL8SJQ="
}
},
{
"type": "step",
"result": "x=3,\\:x=-3"
}
],
"meta": {
"solvingClass": "Equations",
"interimType": "Generic Solve Title 1Eq"
}
},
{
"type": "step",
"primary": "The following points are undefined",
"result": "x=3,\\:x=-3"
}
],
"meta": {
"interimType": "Undefined Points 0Eq",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7yzmeFdjgvhQTm0mwfI9L6sy4e6jK4kujI4ULqoVJMyDD8IqnVMcxtixJKRV0/m09gNghAZYORfq9JtKwOORytPfV2oqc+75VRNLwQrPQk9pugt1g9hg3EUIob9qhnfZUgQUxJPyUNnGfVirkcwpVO92jAB5RE7BOdqi256y9oUI/L/NWLiz7WlXYJyi0meZnYoDSQN4diQ31DYw8UMxnuQ=="
}
},
{
"type": "step",
"primary": "The function domain",
"result": "x<-3\\lor\\:-3<x<3\\lor\\:x>3"
}
],
"meta": {
"solvingClass": "Function Domain"
}
},
"plot_output": {
"meta": {
"plotInfo": {
"variable": "x",
"plotRequest": "\\frac{x+9}{x^{2}-9}"
},
"showViewLarger": true
}
},
"meta": {
"showVerify": true
}
}
Solution
domain
Solution
+1
Interval Notation
Solution steps
Find undefined (singularity) points:
The function domain
Graph
Popular Examples
line y-2=-2/3 (x-4)line inverse of ln(x^3)inverse slope of-4x+7=2y-3slope slope ofintercept 5x+y=-5slope intercept inverse of f(x)=(e^{4x})/(3+e^{4x)}inverse
Frequently Asked Questions (FAQ)
What is the domain of (x+9)/(x^2-9) ?
The domain of (x+9)/(x^2-9) is x<-3\lor-3<x<3\lor x>3