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July 22, 2014

July 22, 2014

Posted by **nadia** on Saturday, November 10, 2012 at 6:13pm.

a) sin 13pi/6 b) cos 11pi/8

c) tan 7pi/4

- Advance fuctions -
**Reiny**, Saturday, November 10, 2012 at 6:40pma) sin(13π/6)

= sin(2π + π/6)

so we are in quadrant I with an angle of sin π/6

sin π/6 = 1/2

cos(11π/6)

= cos(2π-π/6) .... ( think: 330° = 360° - 30°)

so we are in quad IV and in IV the cosine is positive

= cos π/6 = √3/2

c) tan 7π/4

= tan (2π - π/4) ------ in IV where the tangent is negative

= -tan π/4 = -1

You can and should check your answers with a calculator.

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