Algebra &Trigonometry
Sullivan & Sullivan, Fourth Edition
§ 6.4
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Trig Functions of General Angles
Trig Functions of General Angles
A point on the terminal side of an angle is given. Find the exact value of each of the six
trigonometric functions. Be mindful of your signs!
1) (21, -20)
2) (-15, -8)
Signs of Trig Functions, and Quadrants
For each quadrant, draw an angle in it, sketch out a triangle, and use the triangle to explain why
the listed trig function is positive in that quadrant, or negative in that quadrant
3) For the Sin function:
II
I
III
IV
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Algebra &Trigonometry
Sullivan & Sullivan, Fourth Edition
§ 6.4
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4) For the Cos funnction:
II
I
III
IV
5) For the Tan function:
II
III
I
IV
Signs of Trig Functions, and Quadrants
Here, you are given the value of one of the functions and the quadrant of the angle. Use this
information to find the other five trig ratios. Be mindful of your signs!
6) sin  
5
,
13
quadrant II
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Algebra &Trigonometry
Sullivan & Sullivan, Fourth Edition
7) cot  
§ 6.4
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7
, quadrant III
24
2
3
8) cos   , tan   0
Coterminal Angles
For each angle given, find a coterminal angle that's between 0° and 360°, then use that information
to find an exact value, without using your calculator.
9) cos 405°
10) sin 390°
Reference Angles
Find the reference angle and then compute the exact value of Sinθ, Cosθ, and Tanθ.
11) 210°
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Algebra &Trigonometry
Sullivan & Sullivan, Fourth Edition
§ 6.4
12) 690°
13) –240°
14)
7
6
15)
33
4
16) 
2
3
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