{
"query": {
"display": "$$\\sqrt{2}\\cos\\left(x\\right)-1=0,\\:0\\le\\:x\\le\\:2π$$",
"symbolab_question": "EQUATION#\\sqrt{2}\\cos(x)-1=0,0\\le x\\le 2π"
},
"solution": {
"level": "PERFORMED",
"subject": "Trigonometry",
"topic": "Trig Equations",
"subTopic": "Trig Equations",
"default": "x=\\frac{π}{4},x=\\frac{7π}{4}",
"degrees": "x=45^{\\circ },x=315^{\\circ }",
"meta": {
"showVerify": true
}
},
"steps": {
"type": "interim",
"title": "$$\\sqrt{2}\\cos\\left(x\\right)-1=0,\\:0\\le\\:x\\le\\:2π{\\quad:\\quad}x=\\frac{π}{4},\\:x=\\frac{7π}{4}$$",
"input": "\\sqrt{2}\\cos\\left(x\\right)-1=0,\\:0\\le\\:x\\le\\:2π",
"steps": [
{
"type": "interim",
"title": "Move $$1\\:$$to the right side",
"input": "\\sqrt{2}\\cos\\left(x\\right)-1=0",
"result": "\\sqrt{2}\\cos\\left(x\\right)=1",
"steps": [
{
"type": "step",
"primary": "Add $$1$$ to both sides",
"result": "\\sqrt{2}\\cos\\left(x\\right)-1+1=0+1"
},
{
"type": "step",
"primary": "Simplify",
"result": "\\sqrt{2}\\cos\\left(x\\right)=1"
}
],
"meta": {
"interimType": "Move to the Right Title 1Eq",
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}
},
{
"type": "interim",
"title": "Divide both sides by $$\\sqrt{2}$$",
"input": "\\sqrt{2}\\cos\\left(x\\right)=1",
"result": "\\cos\\left(x\\right)=\\frac{\\sqrt{2}}{2}",
"steps": [
{
"type": "step",
"primary": "Divide both sides by $$\\sqrt{2}$$",
"result": "\\frac{\\sqrt{2}\\cos\\left(x\\right)}{\\sqrt{2}}=\\frac{1}{\\sqrt{2}}"
},
{
"type": "interim",
"title": "Simplify",
"input": "\\frac{\\sqrt{2}\\cos\\left(x\\right)}{\\sqrt{2}}=\\frac{1}{\\sqrt{2}}",
"result": "\\cos\\left(x\\right)=\\frac{\\sqrt{2}}{2}",
"steps": [
{
"type": "interim",
"title": "Simplify $$\\frac{\\sqrt{2}\\cos\\left(x\\right)}{\\sqrt{2}}:{\\quad}\\cos\\left(x\\right)$$",
"input": "\\frac{\\sqrt{2}\\cos\\left(x\\right)}{\\sqrt{2}}",
"steps": [
{
"type": "step",
"primary": "Cancel the common factor: $$\\sqrt{2}$$",
"result": "=\\cos\\left(x\\right)"
}
],
"meta": {
"solvingClass": "Solver",
"interimType": "Generic Simplify Specific 1Eq",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s74DwjiBDVBIb8+yh6fkkMMaaVueIzGPhcS6MNJUrXNW4kKHFGvyocNUizdTmaAyO8q47vuWedXv2WUg94ER8IwasnM+lFdK+lbOA6QVAeavaBBTEk/JQ2cZ9WKuRzClU7QG+dQXHhPmuaaYlTGyzk2a8audweY9KIVydfJkmL1iCn8QoAqXqo32pGMW2McTRgFkVDw5yEF2DEw4msQzKTew=="
}
},
{
"type": "interim",
"title": "Simplify $$\\frac{1}{\\sqrt{2}}:{\\quad}\\frac{\\sqrt{2}}{2}$$",
"input": "\\frac{1}{\\sqrt{2}}",
"steps": [
{
"type": "step",
"primary": "Multiply by the conjugate $$\\frac{\\sqrt{2}}{\\sqrt{2}}$$",
"result": "=\\frac{1\\cdot\\:\\sqrt{2}}{\\sqrt{2}\\sqrt{2}}",
"meta": {
"title": {
"extension": "To rationalize the denominator, multiply numerator and denominator by the conjugate of the radical $$\\sqrt{2}$$"
}
}
},
{
"type": "step",
"primary": "$$1\\cdot\\:\\sqrt{2}=\\sqrt{2}$$"
},
{
"type": "interim",
"title": "$$\\sqrt{2}\\sqrt{2}=2$$",
"input": "\\sqrt{2}\\sqrt{2}",
"result": "=\\frac{\\sqrt{2}}{2}",
"steps": [
{
"type": "step",
"primary": "Apply radical rule: $$\\sqrt{a}\\sqrt{a}=a$$",
"secondary": [
"$$\\sqrt{2}\\sqrt{2}=2$$"
],
"result": "=2",
"meta": {
"practiceLink": "/practice/radicals-practice",
"practiceTopic": "Radical Rules"
}
}
],
"meta": {
"solvingClass": "Solver",
"interimType": "Solver",
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}
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"meta": {
"solvingClass": "Solver",
"interimType": "Generic Simplify Specific 1Eq",
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}
},
{
"type": "step",
"result": "\\cos\\left(x\\right)=\\frac{\\sqrt{2}}{2}"
}
],
"meta": {
"interimType": "Generic Simplify 0Eq"
}
}
],
"meta": {
"interimType": "Divide Both Sides Specific 1Eq",
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}
},
{
"type": "interim",
"title": "General solutions for $$\\cos\\left(x\\right)=\\frac{\\sqrt{2}}{2}$$",
"result": "x=\\frac{π}{4}+2πn,\\:x=\\frac{7π}{4}+2πn",
"steps": [
{
"type": "step",
"primary": "$$\\cos\\left(x\\right)$$ periodicity table with $$2πn$$ cycle:<br/>$$\\begin{array}{|c|c|c|c|}\\hline x&\\cos(x)&x&\\cos(x)\\\\\\hline 0&1&π&-1\\\\\\hline \\frac{π}{6}&\\frac{\\sqrt{3}}{2}&\\frac{7π}{6}&-\\frac{\\sqrt{3}}{2}\\\\\\hline \\frac{π}{4}&\\frac{\\sqrt{2}}{2}&\\frac{5π}{4}&-\\frac{\\sqrt{2}}{2}\\\\\\hline \\frac{π}{3}&\\frac{1}{2}&\\frac{4π}{3}&-\\frac{1}{2}\\\\\\hline \\frac{π}{2}&0&\\frac{3π}{2}&0\\\\\\hline \\frac{2π}{3}&-\\frac{1}{2}&\\frac{5π}{3}&\\frac{1}{2}\\\\\\hline \\frac{3π}{4}&-\\frac{\\sqrt{2}}{2}&\\frac{7π}{4}&\\frac{\\sqrt{2}}{2}\\\\\\hline \\frac{5π}{6}&-\\frac{\\sqrt{3}}{2}&\\frac{11π}{6}&\\frac{\\sqrt{3}}{2}\\\\\\hline \\end{array}$$"
},
{
"type": "step",
"result": "x=\\frac{π}{4}+2πn,\\:x=\\frac{7π}{4}+2πn"
}
],
"meta": {
"interimType": "Trig General Solutions cos 1Eq"
}
},
{
"type": "step",
"primary": "Solutions for the range $$0\\le\\:x\\le\\:2π$$",
"result": "x=\\frac{π}{4},\\:x=\\frac{7π}{4}"
}
],
"meta": {
"solvingClass": "Trig Equations",
"practiceLink": "/practice/trigonometry-practice#area=main&subtopic=Trig%20Equations",
"practiceTopic": "Trig Equations"
}
},
"plot_output": {
"meta": {
"plotInfo": {
"variable": "x",
"plotRequest": "\\sqrt{2}\\cos(x)-1,0\\le x\\le 2π"
},
"showViewLarger": true
}
},
"meta": {
"showVerify": true
}
}
Solution
Solution
+1
Degrees
Solution steps
Move to the right side
Add to both sides
Simplify
Divide both sides by
Divide both sides by
Simplify
Simplify
Cancel the common factor:
Simplify
Multiply by the conjugate
Apply radical rule:
General solutions for
periodicity table with cycle:
Solutions for the range
Graph
Popular Examples
Frequently Asked Questions (FAQ)
What is the general solution for sqrt(2)cos(x)-1=0,0<= x<= 2pi ?
The general solution for sqrt(2)cos(x)-1=0,0<= x<= 2pi is x= pi/4 ,x=(7pi)/4