Posted by **JOHN** on Wednesday, January 4, 2012 at 10:05pm.

evaluate the trigonometric function of the given quadrantal angle.

tan 1400°

cos 9π

cos 13π/2

sin (-17π)

- Pre Calc -
**Reiny**, Wednesday, January 4, 2012 at 10:34pm
subtract multiple of 360° (1400/360 = 3.8..

so

tan 1400°

= tan320° , 320 is in IV and 40° from the x-axis

= -tan40

= ....

cos 9π

= cos π , (took away 4 multiples of 2π)

= -1

cos 13π/2

= cos π/2 (took away 6π)

= 0

sin(-17π)

= sin(-17π + 18π) , ( I added 9 rotations)

= sin π

= 0

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