SOLUTION: 20 sin2 x + 21 sin x + 4 = 0 solving trigonometric equations (0,2pi)

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Question 786384: 20 sin2 x + 21 sin x + 4 = 0
solving trigonometric equations (0,2pi)
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
20+sin%5E2+%28x%29+%2B+21+sin+%28x%29+%2B+4+=+0
20+sin%5E2+%28x%29+%2B+16sin%28x%29%2B5+sin+%28x%29+%2B+4+=+0

4sin%28x%29%285sin%28x%29%2B4%29%2B1%285sin%28x%29%2B4%29=0

(5sin(x)+4)((4sin(x)+1)=0
sin(x)=-4/5 OR sinx=-1/4

Now apply (0,2pi)