SOLUTION: If x^4+(1/x^4)=731, find the value of x^2-(1/x^2). thank you

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Question 9384: If x^4+(1/x^4)=731, find the value of x^2-(1/x^2).
thank you
Answer by askmemath(368) About Me  (Show Source):
You can put this solution on YOUR website!
X^4 + (1/X^4) = (X^2 - (1/X^2))^2 + 2
But we know X^4 + (1/X^4) = 731
So 731 = (X^2 - (1/X^2))^2 + 2
or (X^2 - (1/X^2))^2 = 731 - 2
= (X^2 - (1/X^2))^2 = 729

= (X^2 - (1/X^2)) = 27