Question

一道分式计算题!（1-x）分之1+（1+x的平方）分之2+（1+x）分之1

Answer 1

原式=[1/(1-x)+1/(1+x)]+2/(1+x^2)

=[(1+x+1-x)/(1-x)(1+x)]+2/(1+x^2)

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

=2[(1+x^2)+(1-x^2)]/[(1+x^2)(1-x^2)]

=4/(1-x^4)