Question 1090342
2cos^2 x + sinx - 1 = 0
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Sub for cos^2
2(1-sin^2) + sin - 1 = 0
2sin^2 - sin - 1 = 0
(2sin + 1)*(sin - 1) = 0
sin(x) = 1
sin(x) = -1/2
etc