найдите производную функции ( x^3+1)/(x^2+1)

(3x^2(x^2+1)-2x(x^3+1))/(x^2+1)^2=(3x^4+3x^2-2x^4-2x)/(x^2+1)^2=(x^4+3x^2-2x)/(x^2+1)^2=x(x^3+3x-2)/(x^2+1)^2