十字相乘的.已知(2x²+2y²)(x²-2+y²)-16=0,求x的四次方+y的四次方+2x²y²的值.

问题描述:

十字相乘的.已知(2x²+2y²)(x²-2+y²)-16=0,求x的四次方+y的四次方+2x²y²的值.

(2x²+2y²)(x²-2+y²)-16=02(x²+y²)(x²+y²-2)=16(x²+y²)(x²+y²-2)=8(x²+y²)²-2(x²+y²)=8设x²+y²=t (t...