If x^2+(1/x^2)=3, x^4+(1/x^4)=?
Options:
A) 7
B) 11
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)=3^2-2=7.   Thus, the answer is 7.
<result>A</result>
If x^2+(1/x^2)=3, x^4+(1/x^4)=?