If x^2+(1/x^2)=7, x^4+(1/x^4)=? Choose the correct choice from the following: A) 10 B) 11 C) 12 D) 14 E) 47
-&gt; x^4+(1/x^4)=(x^2)^2+(1/x^2)^2=(x^2+1/x^2)^2-2x^2(1/x^2)=7^2-2=47.   Thus, the answer is 47.
<result>E</result>
If x^2+(1/x^2)=7, x^4+(1/x^4)=?