{
"query": {
"display": "$$\\cos\\left(\\frac{5π}{12}\\right)+\\cos\\left(\\frac{π}{12}\\right)$$",
"symbolab_question": "TRIG_EVALUATE#\\cos(\\frac{5π}{12})+\\cos(\\frac{π}{12})"
},
"solution": {
"level": "PERFORMED",
"subject": "Trigonometry",
"topic": "Evaluate Functions",
"subTopic": "Simplified",
"default": "\\sqrt{\\frac{3}{2}}",
"decimal": "1.22474…",
"meta": {
"showVerify": true
}
},
"steps": {
"type": "interim",
"title": "$$\\cos\\left(\\frac{5π}{12}\\right)+\\cos\\left(\\frac{π}{12}\\right)=\\sqrt{\\frac{3}{2}}$$",
"input": "\\cos\\left(\\frac{5π}{12}\\right)+\\cos\\left(\\frac{π}{12}\\right)",
"steps": [
{
"type": "interim",
"title": "Rewrite using trig identities:$${\\quad}2\\cos\\left(\\frac{π}{4}\\right)\\cos\\left(\\frac{π}{6}\\right)$$",
"input": "\\cos\\left(\\frac{5π}{12}\\right)+\\cos\\left(\\frac{π}{12}\\right)",
"result": "=2\\cos\\left(\\frac{π}{4}\\right)\\cos\\left(\\frac{π}{6}\\right)",
"steps": [
{
"type": "step",
"primary": "Use the Sum to Product identity: $$\\cos\\left(s\\right)+\\cos\\left(t\\right)=2\\cos\\left(\\frac{s+t}{2}\\right)\\cos\\left(\\frac{s-t}{2}\\right)$$",
"result": "=2\\cos\\left(\\frac{\\frac{5π}{12}+\\frac{π}{12}}{2}\\right)\\cos\\left(\\frac{\\frac{5π}{12}-\\frac{π}{12}}{2}\\right)"
},
{
"type": "interim",
"title": "Simplify:$${\\quad}\\frac{\\frac{5π}{12}+\\frac{π}{12}}{2}=\\frac{π}{4}$$",
"input": "\\frac{\\frac{5π}{12}+\\frac{π}{12}}{2}",
"steps": [
{
"type": "interim",
"title": "Combine the fractions $$\\frac{5π}{12}+\\frac{π}{12}:{\\quad}\\frac{π}{2}$$",
"result": "=\\frac{\\frac{π}{2}}{2}",
"steps": [
{
"type": "step",
"primary": "Apply rule $$\\frac{a}{c}\\pm\\frac{b}{c}=\\frac{a\\pm\\:b}{c}$$",
"result": "=\\frac{5π+π}{12}"
},
{
"type": "step",
"primary": "Add similar elements: $$5π+π=6π$$",
"result": "=\\frac{6π}{12}"
},
{
"type": "step",
"primary": "Cancel the common factor: $$6$$",
"result": "=\\frac{π}{2}"
}
],
"meta": {
"interimType": "LCD Top Title 1Eq"
}
},
{
"type": "step",
"primary": "Apply the fraction rule: $$\\frac{\\frac{b}{c}}{a}=\\frac{b}{c\\:\\cdot\\:a}$$",
"result": "=\\frac{π}{2\\cdot\\:2}"
},
{
"type": "step",
"primary": "Multiply the numbers: $$2\\cdot\\:2=4$$",
"result": "=\\frac{π}{4}"
}
],
"meta": {
"solvingClass": "Solver",
"interimType": "Generic Simplify Title 0Eq"
}
},
{
"type": "interim",
"title": "Simplify:$${\\quad}\\frac{\\frac{5π}{12}-\\frac{π}{12}}{2}=\\frac{π}{6}$$",
"input": "\\frac{\\frac{5π}{12}-\\frac{π}{12}}{2}",
"steps": [
{
"type": "interim",
"title": "Combine the fractions $$\\frac{5π}{12}-\\frac{π}{12}:{\\quad}\\frac{π}{3}$$",
"result": "=\\frac{\\frac{π}{3}}{2}",
"steps": [
{
"type": "step",
"primary": "Apply rule $$\\frac{a}{c}\\pm\\frac{b}{c}=\\frac{a\\pm\\:b}{c}$$",
"result": "=\\frac{5π-π}{12}"
},
{
"type": "step",
"primary": "Add similar elements: $$5π-π=4π$$",
"result": "=\\frac{4π}{12}"
},
{
"type": "step",
"primary": "Cancel the common factor: $$4$$",
"result": "=\\frac{π}{3}"
}
],
"meta": {
"interimType": "LCD Top Title 1Eq"
}
},
{
"type": "step",
"primary": "Apply the fraction rule: $$\\frac{\\frac{b}{c}}{a}=\\frac{b}{c\\:\\cdot\\:a}$$",
"result": "=\\frac{π}{3\\cdot\\:2}"
},
{
"type": "step",
"primary": "Multiply the numbers: $$3\\cdot\\:2=6$$",
"result": "=\\frac{π}{6}"
}
],
"meta": {
"solvingClass": "Solver",
"interimType": "Generic Simplify Title 0Eq"
}
},
{
"type": "step",
"result": "=2\\cos\\left(\\frac{π}{4}\\right)\\cos\\left(\\frac{π}{6}\\right)"
}
],
"meta": {
"interimType": "Trig Rewrite Using Trig identities Title 0Eq"
}
},
{
"type": "interim",
"title": "Use the following trivial identity:$${\\quad}\\cos\\left(\\frac{π}{4}\\right)=\\frac{\\sqrt{2}}{2}$$",
"input": "\\cos\\left(\\frac{π}{4}\\right)",
"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": "=\\frac{\\sqrt{2}}{2}"
}
],
"meta": {
"interimType": "Trig Trivial Angle Value Title 0Eq"
}
},
{
"type": "interim",
"title": "Use the following trivial identity:$${\\quad}\\cos\\left(\\frac{π}{6}\\right)=\\frac{\\sqrt{3}}{2}$$",
"input": "\\cos\\left(\\frac{π}{6}\\right)",
"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": "=\\frac{\\sqrt{3}}{2}"
}
],
"meta": {
"interimType": "Trig Trivial Angle Value Title 0Eq"
}
},
{
"type": "step",
"result": "=2\\cdot\\:\\frac{\\sqrt{2}}{2}\\cdot\\:\\frac{\\sqrt{3}}{2}"
},
{
"type": "interim",
"title": "Simplify $$2\\cdot\\:\\frac{\\sqrt{2}}{2}\\cdot\\:\\frac{\\sqrt{3}}{2}:{\\quad}\\sqrt{\\frac{3}{2}}$$",
"input": "2\\cdot\\:\\frac{\\sqrt{2}}{2}\\cdot\\:\\frac{\\sqrt{3}}{2}",
"result": "=\\sqrt{\\frac{3}{2}}",
"steps": [
{
"type": "step",
"primary": "Multiply fractions: $$a\\cdot\\frac{b}{c}\\cdot\\frac{d}{e}=\\frac{a\\:\\cdot\\:b\\:\\cdot\\:d}{c\\:\\cdot\\:e}$$",
"result": "=\\frac{\\sqrt{2}\\sqrt{3}\\cdot\\:2}{2\\cdot\\:2}"
},
{
"type": "step",
"primary": "Cancel the common factor: $$2$$",
"result": "=\\frac{\\sqrt{2}\\sqrt{3}}{2}"
},
{
"type": "step",
"primary": "Apply radical rule: $$\\sqrt[n]{a}=a^{\\frac{1}{n}}$$",
"secondary": [
"$$\\sqrt{2}=2^{\\frac{1}{2}}$$"
],
"result": "=\\frac{2^{\\frac{1}{2}}\\sqrt{3}}{2}",
"meta": {
"practiceLink": "/practice/radicals-practice",
"practiceTopic": "Radical Rules"
}
},
{
"type": "step",
"primary": "Apply exponent rule: $$\\frac{x^{a}}{x^{b}}=\\frac{1}{x^{b-a}}$$",
"secondary": [
"$$\\frac{2^{\\frac{1}{2}}}{2^{1}}=\\frac{1}{2^{1-\\frac{1}{2}}}$$"
],
"result": "=\\frac{\\sqrt{3}}{2^{1-\\frac{1}{2}}}",
"meta": {
"practiceLink": "/practice/exponent-practice",
"practiceTopic": "Expand FOIL"
}
},
{
"type": "step",
"primary": "Subtract the numbers: $$1-\\frac{1}{2}=\\frac{1}{2}$$",
"result": "=\\frac{\\sqrt{3}}{2^{\\frac{1}{2}}}"
},
{
"type": "step",
"primary": "Apply radical rule: $$a^{\\frac{1}{n}}=\\sqrt[n]{a}$$",
"secondary": [
"$$2^{\\frac{1}{2}}=\\sqrt{2}$$"
],
"result": "=\\frac{\\sqrt{3}}{\\sqrt{2}}",
"meta": {
"practiceLink": "/practice/radicals-practice",
"practiceTopic": "Radical Rules"
}
},
{
"type": "step",
"primary": "Combine same powers : $$\\frac{\\sqrt{x}}{\\sqrt{y}}=\\sqrt{\\frac{x}{y}}$$",
"result": "=\\sqrt{\\frac{3}{2}}"
}
],
"meta": {
"solvingClass": "Solver",
"interimType": "Generic Simplify Specific 1Eq",
"gptData": "pG0PljGlka7rWtIVHz2xymbOTBTIQkBEGSNjyYYsjjDErT97kX84sZPuiUzCW6s7/OsC643lXZbU+VEjF1qvihqxDwJ92JV1QKn+tjCIbSEJr9fcKtGOvM3Tu2Nnvco3iJ7qJvbOf36tmN4DMHd31QOfOVs9mPIqDLV5QIWwt3kULfQ2PlgyGQK03mK0UmF0E1J+51NQ1TnXtcinw7AvffC30sSftAIFS6Qkpy19Ikp0x8irWzKvvppKMUvqTrnrCa/X3CrRjrzN07tjZ73KNw8dCbJqMwzc7hfouUCYDF8m/e8+HIkQc4F7XJ2JfHIpbqwnNL+vkns16SbvknXX+A=="
}
}
],
"meta": {
"solvingClass": "Trig Evaluate",
"practiceLink": "/practice/trigonometry-practice#area=main&subtopic=Evaluate%20Functions",
"practiceTopic": "Evaluate Functions"
}
},
"meta": {
"showVerify": true
}
}
Solution
Solution
+1
Decimal
Solution steps
Rewrite using trig identities:
Use the Sum to Product identity:
Simplify:
Combine the fractions
Apply rule
Add similar elements:
Cancel the common factor:
Apply the fraction rule:
Multiply the numbers:
Simplify:
Combine the fractions
Apply rule
Add similar elements:
Cancel the common factor:
Apply the fraction rule:
Multiply the numbers:
Use the following trivial identity:
periodicity table with cycle:
Use the following trivial identity:
periodicity table with cycle:
Simplify
Multiply fractions:
Cancel the common factor:
Apply radical rule:
Apply exponent rule:
Subtract the numbers:
Apply radical rule:
Combine same powers :
Popular Examples
Frequently Asked Questions (FAQ)
What is the value of cos((5pi)/(12))+cos(pi/(12)) ?
The value of cos((5pi)/(12))+cos(pi/(12)) is sqrt(3/2)