If x^2+(1/x^2)=2, x^4+(1/x^4)=? Choose the correct choice from the following answers
A) 10
B) 2
C) 12
D) 14
E) 15

Rationale: - > x ^ 4 + ( 1 / x ^ 4 ) = ( x ^ 2 ) ^ 2 + ( 1 / x ^ 2 ) ^ 2 = ( x ^ 2 + 1 / x ^ 2 ) ^ 2 - 2 x ^ 2 ( 1 / x ^ 2 ) = 2 ^ 2 - 2 = 2 . thus , the answer is b .
Answer: B