SOLUTION: How do I approach the following question: If x sin A + y cos A = p and x cos A - y sin A = q, find x square + y square.

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Question 391597: How do I approach the following question: If x sin A + y cos A = p and x cos A - y sin A = q, find x square + y square.
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
= q cos A - p sin A
= p cos A - q sin A
after using Cramer's rule to solve for x and y.
Then
x%5E2+%2B+y%5E2
=
=
=p%5E2+%2B+q%5E2+-+2pq+sin+2A.