If $x - \frac{1}{x}=11,$ What is the value of $(x^4 +\frac{1}{x^4})$?
Answer & explanation
Correct answer: option 3
$(x - \frac{1}{x}) = a$
(x2 + x-2) = (a)2 + 2 = b
= (x4 + x-4) = b2 - 2
If $x - \frac{1}{x}=11,$
(x2 + x-2) = (11)2 + 2 = 123
(x4 + x-4) = 1232 - 2 = 15127