Content

Trigonometry
 
    The Trigonometric Functions
 
    The Values of Common Angles of Trigonometric Functions
 
    The Laws of Trigonometric Functions
 
    The Law of Sines
    
 
    The Law of Cosines
    
 
    The 
        Trigonometric Identities
 
    The Identities of Negative Angle
 
    The Identities of CoFunction 
    
 
    The Identities of Periodicity
    
 
    The Reduction Formulas of Trigonometric Functions
 
    The Identities of Angle Sum and Difference
    
 
    The Pythagorean identity
    
 
    The Identities of Double Angle
    
 
    The Identities of Half Angle
    
 
    The 
    Product of Cosine and Sine

Trigonometry

The Trigonometric Functions

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The Values of Common Angles of Trigonometric Functions

Degrees	Radians	sin θ	cos θ	tan θ	cot θ	sec θ	csc θ
0	0	0	1	0	undefined	1	undefined
30	π/6	1/2	√3/2	√3/3	√3	2√3/3	2
45	π/4	√2/2	√2/2	1	1	√2	√2
60	π/3	√3/2	1/2	√3	√3/3	2	2√3/3
90	π/2	1	0	undefined	0	undefined	1
120	2π/3	√3/2	-1/2	-√3	-√3/3	-2	2√3/3
135	3π/4	√2/2	-√2/2	-1	-1	-√2	√2
150	5π/6	1/2	-√3/2	-√3/3	-√3	-2√3/3	2
180	π	0	-1	0	undefined	-1	undefined
210	7π/6	-1/2	-√3/2	√3/3	√3	-2√3/3	-2
225	5π/4	-√2/2	-√2/2	1	1	-√2	-√2
240	4π/3	-√3/2	-1/2	√3	√3/3	-2	-2√3/3
270	3π/2	-1	0	undefined	0	undefined	-1
300	5π/3	-√3/2	1/2	-√3	-√3/3	2	-2√3/3
315	7π/4	-√2/2	√2/2	-1	-1	√2	-√2
330	11π/6	-1/2	√3/2	-√3/3	-√3	2√3/3	-2
360	2π	0	1	0	undefined	1	undefined

The Laws of Trigonometric Functions

The Law of Sines

The Law of Cosines

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The Trigonometric Identities

The Identities of Negative Angle

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The Identities of CoFunction

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The Identities of Periodicity

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The Reduction Formulas of Trigonometric Functions

a	sin		cos		tan		cot		sec		csc
Radians	α-θ	α+θ	α-θ	α+θ	α-θ	α+θ	α-θ	α+θ	α-θ	α+θ	α-θ	α+θ
0	-sin θ	sin θ	cos θ	cos θ	-tan θ	tan θ	-cot θ	cot θ	sec θ	sec θ	-csc θ	csc θ
π/2	cos θ	cos θ	sin θ	-sin θ	cot θ	-cot θ	tan θ	-tan θ	csc θ	-csc θ	sec θ	sec θ
π	sin θ	-sin θ	-cos θ	-cos θ	-tan θ	tan θ	-cot θ	cot θ	-sec θ	-sec θ	csc θ	-csc θ
3π/2	-cos θ	-cos θ	-sin θ	sin θ	cot θ	-cot θ	tan θ	-tan θ	-csc θ	csc θ	-sec θ	-sec θ
2πn	-sin θ	sin θ	cos θ	cos θ	-tan θ	tan θ	-cot θ	cot θ	sec θ	sec θ	-csc θ	csc θ