SOLUTION: Hi! I've been working on this problem for quite a while now and I'm still unable to get anywhere! Please help! solve cos2x + 3sinx = -1 for x on [0,2pi] Thanks!

Algebra ->  Trigonometry-basics -> SOLUTION: Hi! I've been working on this problem for quite a while now and I'm still unable to get anywhere! Please help! solve cos2x + 3sinx = -1 for x on [0,2pi] Thanks!      Log On


   

Question 811538: Hi! I've been working on this problem for quite a while now and I'm still unable to get anywhere! Please help!
solve cos2x + 3sinx = -1 for x on [0,2pi]
Thanks!
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
solve cos2x + 3sinx = -1 for x on [0,2pi]
cos^2x-sin^2x+3sinx+1=0
1-sin^2x-sin^2x+3sinx+1=0
2sin^2x-3sinx-2=0
(2sinx+1)(sinx-2)=0
sinx=2(reject, (-1 < sinx < 1)
or
sinx=-1/2
x=7π/, 11π/6