Precalculus Examples

Simplify sin((5pi)/12)cos((13pi)/12)-cos((5pi)/12)sin((13pi)/12)
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
Apply the sum of angles identity.
Step 1.1.3
The exact value of is .
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
Simplify .
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Step 1.1.7.1
Simplify each term.
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Step 1.1.7.1.1
Multiply .
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Step 1.1.7.1.1.1
Multiply by .
Step 1.1.7.1.1.2
Multiply by .
Step 1.1.7.1.2
Multiply .
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Step 1.1.7.1.2.1
Multiply by .
Step 1.1.7.1.2.2
Combine using the product rule for radicals.
Step 1.1.7.1.2.3
Multiply by .
Step 1.1.7.1.2.4
Multiply by .
Step 1.1.7.2
Combine the numerators over the common denominator.
Step 1.2
The exact value of is .
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Step 1.2.1
Apply the reference angle by finding the angle with equivalent trig values in the first quadrant. Make the expression negative because cosine is negative in the third quadrant.
Step 1.2.2
Split into two angles where the values of the six trigonometric functions are known.
Step 1.2.3
Apply the difference of angles identity .
Step 1.2.4
The exact value of is .
Step 1.2.5
The exact value of is .
Step 1.2.6
The exact value of is .
Step 1.2.7
The exact value of is .
Step 1.2.8
Simplify .
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Step 1.2.8.1
Simplify each term.
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Step 1.2.8.1.1
Multiply .
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Step 1.2.8.1.1.1
Multiply by .
Step 1.2.8.1.1.2
Combine using the product rule for radicals.
Step 1.2.8.1.1.3
Multiply by .
Step 1.2.8.1.1.4
Multiply by .
Step 1.2.8.1.2
Multiply .
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Step 1.2.8.1.2.1
Multiply by .
Step 1.2.8.1.2.2
Multiply by .
Step 1.2.8.2
Combine the numerators over the common denominator.
Step 1.3
Multiply .
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Step 1.3.1
Multiply by .
Step 1.3.2
Multiply by .
Step 1.4
Expand using the FOIL Method.
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Step 1.4.1
Apply the distributive property.
Step 1.4.2
Apply the distributive property.
Step 1.4.3
Apply the distributive property.
Step 1.5
Simplify and combine like terms.
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Step 1.5.1
Simplify each term.
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Step 1.5.1.1
Combine using the product rule for radicals.
Step 1.5.1.2
Multiply by .
Step 1.5.1.3
Rewrite as .
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Step 1.5.1.3.1
Factor out of .
Step 1.5.1.3.2
Rewrite as .
Step 1.5.1.4
Pull terms out from under the radical.
Step 1.5.1.5
Combine using the product rule for radicals.
Step 1.5.1.6
Multiply by .
Step 1.5.1.7
Rewrite as .
Step 1.5.1.8
Pull terms out from under the radical, assuming positive real numbers.
Step 1.5.1.9
Combine using the product rule for radicals.
Step 1.5.1.10
Multiply by .
Step 1.5.1.11
Rewrite as .
Step 1.5.1.12
Pull terms out from under the radical, assuming positive real numbers.
Step 1.5.1.13
Combine using the product rule for radicals.
Step 1.5.1.14
Multiply by .
Step 1.5.1.15
Rewrite as .
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Step 1.5.1.15.1
Factor out of .
Step 1.5.1.15.2
Rewrite as .
Step 1.5.1.16
Pull terms out from under the radical.
Step 1.5.2
Add and .
Step 1.5.3
Add and .
Step 1.6
Cancel the common factor of and .
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Step 1.6.1
Factor out of .
Step 1.6.2
Factor out of .
Step 1.6.3
Factor out of .
Step 1.6.4
Cancel the common factors.
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Step 1.6.4.1
Factor out of .
Step 1.6.4.2
Cancel the common factor.
Step 1.6.4.3
Rewrite the expression.
Step 1.7
The exact value of is .
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Step 1.7.1
Split into two angles where the values of the six trigonometric functions are known.
Step 1.7.2
Apply the sum of angles identity .
Step 1.7.3
The exact value of is .
Step 1.7.4
The exact value of is .
Step 1.7.5
The exact value of is .
Step 1.7.6
The exact value of is .
Step 1.7.7
Simplify .
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Step 1.7.7.1
Simplify each term.
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Step 1.7.7.1.1
Multiply .
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Step 1.7.7.1.1.1
Multiply by .
Step 1.7.7.1.1.2
Combine using the product rule for radicals.
Step 1.7.7.1.1.3
Multiply by .
Step 1.7.7.1.1.4
Multiply by .
Step 1.7.7.1.2
Multiply .
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Step 1.7.7.1.2.1
Multiply by .
Step 1.7.7.1.2.2
Multiply by .
Step 1.7.7.2
Combine the numerators over the common denominator.
Step 1.8
The exact value of is .
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Step 1.8.1
Apply the reference angle by finding the angle with equivalent trig values in the first quadrant. Make the expression negative because sine is negative in the third quadrant.
Step 1.8.2
Split into two angles where the values of the six trigonometric functions are known.
Step 1.8.3
Apply the difference of angles identity.
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
The exact value of is .
Step 1.8.8
Simplify .
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Step 1.8.8.1
Simplify each term.
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Step 1.8.8.1.1
Multiply .
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Step 1.8.8.1.1.1
Multiply by .
Step 1.8.8.1.1.2
Combine using the product rule for radicals.
Step 1.8.8.1.1.3
Multiply by .
Step 1.8.8.1.1.4
Multiply by .
Step 1.8.8.1.2
Multiply .
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Step 1.8.8.1.2.1
Multiply by .
Step 1.8.8.1.2.2
Multiply by .
Step 1.8.8.2
Combine the numerators over the common denominator.
Step 1.9
Multiply .
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Step 1.9.1
Multiply by .
Step 1.9.2
Multiply by .
Step 1.9.3
Multiply by .
Step 1.9.4
Raise to the power of .
Step 1.9.5
Raise to the power of .
Step 1.9.6
Use the power rule to combine exponents.
Step 1.9.7
Add and .
Step 1.9.8
Multiply by .
Step 1.10
Rewrite as .
Step 1.11
Expand using the FOIL Method.
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Step 1.11.1
Apply the distributive property.
Step 1.11.2
Apply the distributive property.
Step 1.11.3
Apply the distributive property.
Step 1.12
Simplify and combine like terms.
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Step 1.12.1
Simplify each term.
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Step 1.12.1.1
Combine using the product rule for radicals.
Step 1.12.1.2
Multiply by .
Step 1.12.1.3
Rewrite as .
Step 1.12.1.4
Pull terms out from under the radical, assuming positive real numbers.
Step 1.12.1.5
Multiply .
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Step 1.12.1.5.1
Combine using the product rule for radicals.
Step 1.12.1.5.2
Multiply by .
Step 1.12.1.6
Rewrite as .
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Step 1.12.1.6.1
Factor out of .
Step 1.12.1.6.2
Rewrite as .
Step 1.12.1.7
Pull terms out from under the radical.
Step 1.12.1.8
Multiply by .
Step 1.12.1.9
Multiply .
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Step 1.12.1.9.1
Combine using the product rule for radicals.
Step 1.12.1.9.2
Multiply by .
Step 1.12.1.10
Rewrite as .
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Step 1.12.1.10.1
Factor out of .
Step 1.12.1.10.2
Rewrite as .
Step 1.12.1.11
Pull terms out from under the radical.
Step 1.12.1.12
Multiply by .
Step 1.12.1.13
Multiply .
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Step 1.12.1.13.1
Multiply by .
Step 1.12.1.13.2
Multiply by .
Step 1.12.1.13.3
Raise to the power of .
Step 1.12.1.13.4
Raise to the power of .
Step 1.12.1.13.5
Use the power rule to combine exponents.
Step 1.12.1.13.6
Add and .
Step 1.12.1.14
Rewrite as .
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Step 1.12.1.14.1
Use to rewrite as .
Step 1.12.1.14.2
Apply the power rule and multiply exponents, .
Step 1.12.1.14.3
Combine and .
Step 1.12.1.14.4
Cancel the common factor of .
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Step 1.12.1.14.4.1
Cancel the common factor.
Step 1.12.1.14.4.2
Rewrite the expression.
Step 1.12.1.14.5
Evaluate the exponent.
Step 1.12.2
Add and .
Step 1.12.3
Subtract from .
Step 1.13
Cancel the common factor of and .
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Step 1.13.1
Factor out of .
Step 1.13.2
Factor out of .
Step 1.13.3
Factor out of .
Step 1.13.4
Cancel the common factors.
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Step 1.13.4.1
Factor out of .
Step 1.13.4.2
Cancel the common factor.
Step 1.13.4.3
Rewrite the expression.
Step 2
Combine the numerators over the common denominator.
Step 3
Simplify each term.
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Step 3.1
Apply the distributive property.
Step 3.2
Multiply by .
Step 4
Simplify terms.
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Step 4.1
Add and .
Step 4.2
Subtract from .
Step 4.3
Subtract from .
Step 4.4
Cancel the common factor of and .
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Step 4.4.1
Factor out of .
Step 4.4.2
Cancel the common factors.
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Step 4.4.2.1
Factor out of .
Step 4.4.2.2
Cancel the common factor.
Step 4.4.2.3
Rewrite the expression.
Step 4.5
Move the negative in front of the fraction.
Step 5
The result can be shown in multiple forms.
Exact Form:
Decimal Form: