If x4 + 1 / x4 = 14159, then value of x + 1 / x is:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e 11
We have given that, x4 + 1 / x4 = 14159
Adding two on both sides we would get,
⇒ x4 + 1 / x4 + 2 = 14161
⇒ (x2 + 1 / x2)2 = 1192
Taking square root in both the sides,
⇒ x2 + 1 / x2 + 2= 121
Adding two on both sides we would get,
⇒ (x + 1 / x)2 = 112
Taking square root in both the sides,
⇒ x + 1 / x = 11