Trigonometric Identities
Fundamental Identities
Pythagorean Identities
Cofunction Identities
Negative Angle Identities
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Addition & Subtraction Identities
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t
Double Angle Identities
Half-Angle Identities
√
√
√
Product Identities
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The Unit Circle Table of Values
Quadrant
Degrees
Radians
Sin 
Cos 
Tan 
Csc 
0°
0
0
1
0
Undefined 1
√
30°
I
45°
I
60°
90°
√
0
1
120°
√
II
135°
√
II
150°
0
III
210°
-
III
225°
III
240°
0
√
√
300°
√
IV
315°
√
IV
330°
√
√
1
√
1
-√
√
-2
0
√
2
√
√
0
Undefined
Undefined
√
-1
√
√
√
√
-1
√
Undefined -1
√
0
√
-2
√
0
√
2
1
0
-2
Undefined -1
√
√
√
2
√
√
√
1
Undefined
√
-1
√
IV
360°
√
-1
-1
√
√
Undefined
√
Undefined 1
√
180°
√
√
Cot 
√
2
1
√
II
270°
√
√
Sec 
-2
Undefined 1
√
√
-1
√
Undefined