把下列各式约分.x的四次方-1/1-x²

问题描述:

把下列各式约分.x的四次方-1/1-x²

(x^4-1)/(1-x^2)
=(x^2-1)(x^2+1)/(1-x^2)
=-(1-x^2)(x^2+1)/(1-x^2)
=-(x^2+1)
=-x^2-1

(x^4-1)/(1-x^2)
=(x^2+1)(x^2-1)/(1-x^2)
=-(x^2+1)
=-x^2-1