If $ x - \frac{1}{x}= 8$, find the value of $x^4 +\frac{1}{x^4}$
Answer & explanation
Correct answer: option 4
$(x - \frac{1}{x}) = a$
(x2 + x-2) = (a)2 + 2 = b
= (x4 + x-4) = b2 - 2
If $ x - \frac{1}{x}= 8$,
(x2 + x-2) = (8)2 + 2 = 66
find the value of $x^4 +\frac{1}{x^4}$ = 662 - 2 = 4356 - 2 = 4354