Trig identity help with LHS?

Trig identity - prove the equation as an identity

1) (cos 2x + cos 2y) / (sin x + cos y) = 2 cos y - 2 sin x

2) sin^4 = (1 - cot^2 x + cos^2 x cot^2 x) / csc^2x
to clarify it's ...cost^2 x times cot^2 x / csc^2x
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