You can put this solution on YOUR website! (csc^2 x-1)sin x = cot x cos x verify the identity
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(1/sin) - sin = cos^2/sin
(1 - sin^2)/sin = cos^2/sin
1 - sin^2 = cos^2
sin^2 + cos^2 = 1
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PS I'm still looking for an example where working 1 side only makes a difference.