x^4+4y^4.因式分解

问题描述:

x^4+4y^4.因式分解

x^4+4y^4
=x^4+4y^4+4x^2y^2-4x^2y^2
=(x^2+2y^2)^2-4x^2y^2
=(x^2+2y^2-2xy)(x^2+2y^2+2xy)
用添项法!