计算:(m^2+n^2)^2-4m^2n^2

问题描述:

计算:(m^2+n^2)^2-4m^2n^2

(m^2+n^2)^2-4m^2n^2
=m^4+n^4+2m^2n^2-4m^2n^2
=m^4+n^4-2m^2n^2
=(m^2-n^2)^2