Trigonometry Examples

Simplify cos(15)^2+cos(75)^2
Step 1
Simplify each term.
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Step 1.1
The exact value of is .
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Step 1.1.1
Split into two angles where the values of the six trigonometric functions are known.
Step 1.1.2
Separate negation.
Step 1.1.3
Apply the difference of angles identity .
Step 1.1.4
The exact value of is .
Step 1.1.5
The exact value of is .
Step 1.1.6
The exact value of is .
Step 1.1.7
The exact value of is .
Step 1.1.8
Simplify .
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Step 1.1.8.1
Simplify each term.
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Step 1.1.8.1.1
Multiply .
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Step 1.1.8.1.1.1
Multiply by .
Step 1.1.8.1.1.2
Combine using the product rule for radicals.
Step 1.1.8.1.1.3
Multiply by .
Step 1.1.8.1.1.4
Multiply by .
Step 1.1.8.1.2
Multiply .
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Step 1.1.8.1.2.1
Multiply by .
Step 1.1.8.1.2.2
Multiply by .
Step 1.1.8.2
Combine the numerators over the common denominator.
Step 1.2
Apply the product rule to .
Step 1.3
Raise to the power of .
Step 1.4
Rewrite as .
Step 1.5
Expand using the FOIL Method.
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Step 1.5.1
Apply the distributive property.
Step 1.5.2
Apply the distributive property.
Step 1.5.3
Apply the distributive property.
Step 1.6
Simplify and combine like terms.
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Step 1.6.1
Simplify each term.
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Step 1.6.1.1
Combine using the product rule for radicals.
Step 1.6.1.2
Multiply by .
Step 1.6.1.3
Rewrite as .
Step 1.6.1.4
Pull terms out from under the radical, assuming positive real numbers.
Step 1.6.1.5
Combine using the product rule for radicals.
Step 1.6.1.6
Multiply by .
Step 1.6.1.7
Rewrite as .
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Step 1.6.1.7.1
Factor out of .
Step 1.6.1.7.2
Rewrite as .
Step 1.6.1.8
Pull terms out from under the radical.
Step 1.6.1.9
Combine using the product rule for radicals.
Step 1.6.1.10
Multiply by .
Step 1.6.1.11
Rewrite as .
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Step 1.6.1.11.1
Factor out of .
Step 1.6.1.11.2
Rewrite as .
Step 1.6.1.12
Pull terms out from under the radical.
Step 1.6.1.13
Combine using the product rule for radicals.
Step 1.6.1.14
Multiply by .
Step 1.6.1.15
Rewrite as .
Step 1.6.1.16
Pull terms out from under the radical, assuming positive real numbers.
Step 1.6.2
Add and .
Step 1.6.3
Add and .
Step 1.7
Cancel the common factor of and .
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Step 1.7.1
Factor out of .
Step 1.7.2
Factor out of .
Step 1.7.3
Factor out of .
Step 1.7.4
Cancel the common factors.
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Step 1.7.4.1
Factor out of .
Step 1.7.4.2
Cancel the common factor.
Step 1.7.4.3
Rewrite the expression.
Step 1.8
The exact value of is .
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Step 1.8.1
Split into two angles where the values of the six trigonometric functions are known.
Step 1.8.2
Apply the sum of angles identity .
Step 1.8.3
The exact value of is .
Step 1.8.4
The exact value of is .
Step 1.8.5
The exact value of is .
Step 1.8.6
The exact value of is .
Step 1.8.7
Simplify .
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Step 1.8.7.1
Simplify each term.
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Step 1.8.7.1.1
Multiply .
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Step 1.8.7.1.1.1
Multiply by .
Step 1.8.7.1.1.2
Combine using the product rule for radicals.
Step 1.8.7.1.1.3
Multiply by .
Step 1.8.7.1.1.4
Multiply by .
Step 1.8.7.1.2
Multiply .
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Step 1.8.7.1.2.1
Multiply by .
Step 1.8.7.1.2.2
Multiply by .
Step 1.8.7.2
Combine the numerators over the common denominator.
Step 1.9
Apply the product rule to .
Step 1.10
Raise to the power of .
Step 1.11
Rewrite as .
Step 1.12
Expand using the FOIL Method.
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Step 1.12.1
Apply the distributive property.
Step 1.12.2
Apply the distributive property.
Step 1.12.3
Apply the distributive property.
Step 1.13
Simplify and combine like terms.
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Step 1.13.1
Simplify each term.
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Step 1.13.1.1
Combine using the product rule for radicals.
Step 1.13.1.2
Multiply by .
Step 1.13.1.3
Rewrite as .
Step 1.13.1.4
Pull terms out from under the radical, assuming positive real numbers.
Step 1.13.1.5
Multiply .
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Step 1.13.1.5.1
Combine using the product rule for radicals.
Step 1.13.1.5.2
Multiply by .
Step 1.13.1.6
Rewrite as .
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Step 1.13.1.6.1
Factor out of .
Step 1.13.1.6.2
Rewrite as .
Step 1.13.1.7
Pull terms out from under the radical.
Step 1.13.1.8
Multiply by .
Step 1.13.1.9
Multiply .
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Step 1.13.1.9.1
Combine using the product rule for radicals.
Step 1.13.1.9.2
Multiply by .
Step 1.13.1.10
Rewrite as .
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Step 1.13.1.10.1
Factor out of .
Step 1.13.1.10.2
Rewrite as .
Step 1.13.1.11
Pull terms out from under the radical.
Step 1.13.1.12
Multiply by .
Step 1.13.1.13
Multiply .
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Step 1.13.1.13.1
Multiply by .
Step 1.13.1.13.2
Multiply by .
Step 1.13.1.13.3
Raise to the power of .
Step 1.13.1.13.4
Raise to the power of .
Step 1.13.1.13.5
Use the power rule to combine exponents.
Step 1.13.1.13.6
Add and .
Step 1.13.1.14
Rewrite as .
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Step 1.13.1.14.1
Use to rewrite as .
Step 1.13.1.14.2
Apply the power rule and multiply exponents, .
Step 1.13.1.14.3
Combine and .
Step 1.13.1.14.4
Cancel the common factor of .
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Step 1.13.1.14.4.1
Cancel the common factor.
Step 1.13.1.14.4.2
Rewrite the expression.
Step 1.13.1.14.5
Evaluate the exponent.
Step 1.13.2
Add and .
Step 1.13.3
Subtract from .
Step 1.14
Cancel the common factor of and .
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Step 1.14.1
Factor out of .
Step 1.14.2
Factor out of .
Step 1.14.3
Factor out of .
Step 1.14.4
Cancel the common factors.
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Step 1.14.4.1
Factor out of .
Step 1.14.4.2
Cancel the common factor.
Step 1.14.4.3
Rewrite the expression.
Step 2
Simplify terms.
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Step 2.1
Combine the numerators over the common denominator.
Step 2.2
Add and .
Step 2.3
Subtract from .
Step 2.4
Simplify the expression.
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Step 2.4.1
Add and .
Step 2.4.2
Divide by .