将x^4-7x^2+1因式分解(过程)

问题描述:

将x^4-7x^2+1因式分解(过程)

x^4-7x^2+1
=x^4+2x^2+1-9x^2
=(x^2+1)^2-(3x)^2
=(x^2-3x+1)(x^2+3x+1).