Trigonometry Examples

Evaluate sec(165)
Step 1
Apply the reference angle by finding the angle with equivalent trig values in the first quadrant. Make the expression negative because secant is negative in the second quadrant.
Step 2
Split into two angles where the values of the six trigonometric functions are known.
Step 3
Separate negation.
Step 4
Apply the difference of angles identity.
Step 5
The exact value of is .
Step 6
The exact value of is .
Step 7
The exact value of is .
Step 8
The exact value of is .
Step 9
The exact value of is .
Step 10
The exact value of is .
Step 11
The exact value of is .
Step 12
The exact value of is .
Step 13
Simplify .
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Step 13.1
Simplify the numerator.
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Step 13.1.1
Multiply by .
Step 13.1.2
Combine and .
Step 13.1.3
Combine and .
Step 13.2
Simplify the denominator.
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Step 13.2.1
Move to the left of .
Step 13.2.2
Multiply by .
Step 13.2.3
Combine and simplify the denominator.
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Step 13.2.3.1
Multiply by .
Step 13.2.3.2
Raise to the power of .
Step 13.2.3.3
Raise to the power of .
Step 13.2.3.4
Use the power rule to combine exponents.
Step 13.2.3.5
Add and .
Step 13.2.3.6
Rewrite as .
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Step 13.2.3.6.1
Use to rewrite as .
Step 13.2.3.6.2
Apply the power rule and multiply exponents, .
Step 13.2.3.6.3
Combine and .
Step 13.2.3.6.4
Cancel the common factor of .
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Step 13.2.3.6.4.1
Cancel the common factor.
Step 13.2.3.6.4.2
Rewrite the expression.
Step 13.2.3.6.5
Evaluate the exponent.
Step 13.2.4
Cancel the common factor of .
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Step 13.2.4.1
Cancel the common factor.
Step 13.2.4.2
Rewrite the expression.
Step 13.2.5
Combine and .
Step 13.2.6
Combine and .
Step 13.2.7
Multiply by .
Step 13.2.8
Combine and simplify the denominator.
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Step 13.2.8.1
Multiply by .
Step 13.2.8.2
Raise to the power of .
Step 13.2.8.3
Raise to the power of .
Step 13.2.8.4
Use the power rule to combine exponents.
Step 13.2.8.5
Add and .
Step 13.2.8.6
Rewrite as .
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Step 13.2.8.6.1
Use to rewrite as .
Step 13.2.8.6.2
Apply the power rule and multiply exponents, .
Step 13.2.8.6.3
Combine and .
Step 13.2.8.6.4
Cancel the common factor of .
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Step 13.2.8.6.4.1
Cancel the common factor.
Step 13.2.8.6.4.2
Rewrite the expression.
Step 13.2.8.6.5
Evaluate the exponent.
Step 13.2.9
Simplify the numerator.
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Step 13.2.9.1
Combine using the product rule for radicals.
Step 13.2.9.2
Multiply by .
Step 13.2.10
To write as a fraction with a common denominator, multiply by .
Step 13.2.11
Combine and .
Step 13.2.12
Combine the numerators over the common denominator.
Step 13.2.13
Multiply by .
Step 13.3
Simplify the numerator.
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Step 13.3.1
Multiply by .
Step 13.3.2
Multiply by .
Step 13.4
Simplify the denominator.
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Step 13.4.1
Combine using the product rule for radicals.
Step 13.4.2
Multiply by .
Step 13.5
Simplify the numerator.
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Step 13.5.1
Combine and into a single radical.
Step 13.5.2
Cancel the common factor of and .
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Step 13.5.2.1
Factor out of .
Step 13.5.2.2
Cancel the common factors.
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Step 13.5.2.2.1
Factor out of .
Step 13.5.2.2.2
Cancel the common factor.
Step 13.5.2.2.3
Rewrite the expression.
Step 13.5.3
Rewrite as .
Step 13.5.4
Any root of is .
Step 13.5.5
Multiply by .
Step 13.5.6
Combine and simplify the denominator.
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Step 13.5.6.1
Multiply by .
Step 13.5.6.2
Raise to the power of .
Step 13.5.6.3
Raise to the power of .
Step 13.5.6.4
Use the power rule to combine exponents.
Step 13.5.6.5
Add and .
Step 13.5.6.6
Rewrite as .
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Step 13.5.6.6.1
Use to rewrite as .
Step 13.5.6.6.2
Apply the power rule and multiply exponents, .
Step 13.5.6.6.3
Combine and .
Step 13.5.6.6.4
Cancel the common factor of .
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Step 13.5.6.6.4.1
Cancel the common factor.
Step 13.5.6.6.4.2
Rewrite the expression.
Step 13.5.6.6.5
Evaluate the exponent.
Step 13.5.7
Combine and .
Step 13.6
Multiply the numerator by the reciprocal of the denominator.
Step 13.7
Cancel the common factor of .
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Step 13.7.1
Cancel the common factor.
Step 13.7.2
Rewrite the expression.
Step 13.8
Combine and .
Step 13.9
Combine and .
Step 13.10
Cancel the common factor of and .
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Step 13.10.1
Factor out of .
Step 13.10.2
Cancel the common factors.
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Step 13.10.2.1
Factor out of .
Step 13.10.2.2
Factor out of .
Step 13.10.2.3
Factor out of .
Step 13.10.2.4
Cancel the common factor.
Step 13.10.2.5
Rewrite the expression.
Step 13.11
Multiply by .
Step 13.12
Multiply by .
Step 13.13
Expand the denominator using the FOIL method.
Step 13.14
Simplify.
Step 13.15
Cancel the common factor of and .
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Step 13.15.1
Factor out of .
Step 13.15.2
Cancel the common factors.
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Step 13.15.2.1
Factor out of .
Step 13.15.2.2
Cancel the common factor.
Step 13.15.2.3
Rewrite the expression.
Step 13.16
Apply the distributive property.
Step 13.17
Multiply .
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Step 13.17.1
Combine using the product rule for radicals.
Step 13.17.2
Multiply by .
Step 13.18
Multiply .
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Step 13.18.1
Combine using the product rule for radicals.
Step 13.18.2
Multiply by .
Step 13.19
Simplify each term.
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Step 13.19.1
Rewrite as .
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Step 13.19.1.1
Factor out of .
Step 13.19.1.2
Rewrite as .
Step 13.19.2
Pull terms out from under the radical.
Step 13.19.3
Multiply by .
Step 13.20
Cancel the common factor of and .
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Step 13.20.1
Factor out of .
Step 13.20.2
Factor out of .
Step 13.20.3
Factor out of .
Step 13.20.4
Cancel the common factors.
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Step 13.20.4.1
Factor out of .
Step 13.20.4.2
Cancel the common factor.
Step 13.20.4.3
Rewrite the expression.
Step 13.20.4.4
Divide by .
Step 13.21
Apply the distributive property.
Step 13.22
Multiply .
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Step 13.22.1
Multiply by .
Step 13.22.2
Multiply by .
Step 14
The result can be shown in multiple forms.
Exact Form:
Decimal Form: