`(1 + sin(y))[1 + sin(-y)] = cos^2(y)` Verfiy the identity.

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embizze eNotes educator| Certified Educator

Verify (1+sin(y))(1-sin(y))=cos^2(y):

Working from the left side we show that it is equivalent to the right side:

(1+sin(y))(1-sin(y))

=1-sin^2(y)

=cos^2(y) using the pythagorean identity