SOLUTION: verify the identity by simplifying the left side sin^2x-sin^2y=cos^2y-cos^2x

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Question 818520: verify the identity by simplifying the left side
sin^2x-sin^2y=cos^2y-cos^2x
Answer by jhunjiro(67) About Me  (Show Source):
You can put this solution on YOUR website!

Given
sin^2x-sin^2y=cos^2y-cos^2x
Solution:
Pythagorean Identity
cos^2x + sin^2y = 1
sin^2Ø = 1 - cos^2Ø

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