SOLUTION: Trig identity help. Proove: (xsin(theta)+ ycos(theta))^2 + (xcos(theta)-ysin(theta))^2 = x^2 +y^2

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Question 736591: Trig identity help.
Proove:
(xsin(theta)+ ycos(theta))^2 + (xcos(theta)-ysin(theta))^2 = x^2 +y^2

Answer by lynnlo(4176)   (Show Source): You can put this solution on YOUR website!
-y cos(2theta ^2)+x sin (theta)+ cos (theta)-x^2=y^2
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