Thursday
December 18, 2014

Homework Help: Trig (Last URGENT)

Posted by Anonymous on Wednesday, February 22, 2012 at 11:11pm.

sin2x+cosx=0 , [-180,180)
= 2sinxcosx+cosx=0
= cosx(2sinx+1)=0
cosx=0
x1=cos^-1(0)
x1=90
x2=360-90
x2=270

270 doesn't fit in [-180,180) what do I do? Or maybe I did something wrong.

sinx=1/2
x1=sin^-1(1/2)
x1=30
x2=180-30
x2=150

is this correct?

Please and Thank you

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