If $x^4 + x^{-4} = 2599$, then one of the values of $x - x^{-1}$, where x > 0, is equal to:
Answer & explanation
Correct answer: option 2
If $K^2+\frac{1}{K^2}$ = n
then, $K+\frac{1}{K}=\sqrt {n + 2}$
If $x^4 + x^{-4} = 2599$
Then one of the values of $x - x^{-1}$ = ?
If $x^4 + x^{-4} = 2599$
then $x^2 + x^{-2}$ = \(\sqrt {2599 + 2}\) = 51
$x - x^{-1}$ = \(\sqrt {51 - 2}\) = 7