SOLUTION: if x-1/x = 3, then how much is x^2 - x^(-2)?

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Question 765343: if x-1/x = 3, then how much is x^2 - x^(-2)?
Answer by ramkikk66(644) About Me  (Show Source):
You can put this solution on YOUR website!

x+-+1%2Fx+=+3 how much x^2 - 1/x^2? (x^(-2) is the same as 1/x^2)

Squaring both sides

%28x+-+1%2Fx%29%5E2+=+x%5E2+-+1%2Fx%5E2+-+2%2Ax%2A1%2Fx

9+=+x%5E2+-+1%2Fx%5E2+-+2

So x%5E2+-+1%2Fx%5E2+=+11

:)