Question

将函数f(x)=x^2/(1+x)展开成的x幕函数

Answer 1

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

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

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

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