SOLUTION: If 2sin^2theta -cos^2theta=2 then theta=?

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Question 1038604: If 2sin^2theta -cos^2theta=2 then theta=?
Answer by ikleyn(52790) About Me  (Show Source):
You can put this solution on YOUR website!
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If 2sin^2theta -cos^2theta=2 then theta=?
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2sin%5E2%28theta%29+-cos%5E2%28theta%29 = 2sin%5E2%28theta%29+-+%281-sin%5E2%28theta%29%29 = 3sin%5E2%28theta%29+-1.


Therefore, if 2sin%5E2%28theta%29+-cos%5E2%28theta%29 = 2 then

3sin%5E2%28theta%29+-1 = 2  --->

3sin%5E2%28theta%29 = 3  --->

sin%5E2%28theta%29 = 1  --->

sin%28theta%29 = +/-1  --->

theta = pi%2F2+%2B+2k%2Api  or  theta = -pi%2F2+%2B+2k%2Api, k = 0, +/-1, +/-2, . . . 

Answer.  theta = pi%2F2+%2B+k%2Api,  k = 0, +/-1, +/-2, . . .