You can put this solution on YOUR website! If 2sin^2θ – cos^2θ = 2
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2sin^2 - (1-sin^2) = 2
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3sin^2 = 3
sin^2 = 1
sin^2-1 = 0
(sin-1)(sin+1) = 0
sin(theta) = 1 or sin(theta) = -1
theta = pi/2 or -pi/2
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Cheers,
Stan H.