If x^2+(1/x^2)=2, x^4+(1/x^4)=?  Choose the correct choice from the following.
A) 10	B) 2	C) 12	D) 14	E) 15
-&gt; x^4+(1/x^4)=(x^2)^2+(1/x^2)^2=(x^2+1/x^2)^2-2x^2(1/x^2)=2^2-2=2.   Thus, the answer is 2.
<result>B</result>
If x^2+(1/x^2)=2, x^4+(1/x^4)=?