Posted by Sara on Saturday, June 19, 2010 at 1:06pm.
Solve for [0, 360)
2sinxcosx + cosx =0
2sinxcosx = cosx
2sinx = cosx/cosx
sinx = 1/2
{210, 330)
Is this correct?

trig  Reiny, Saturday, June 19, 2010 at 5:41pm
no , you only have half the answers
2sinxcosx + cosx =0
cosx(2sinx + 1) = 0
cosx = 0 or sinx = 1/2
if cosx = 0, x = 90° , 270°
if sinx = 1/2, x = 210°, 330°
(you only had the last case)
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