求详细解答过程

let
C= ∫(0->1) f(x) dx
f(x) = 1/(1+x^2) + x^3.∫(0->1) f(x) dx
=1/(1+x^2) + Cx^3
∫(0->1) f(x) dx
= ∫(0->1) [1/(1+x^2) + Cx^3 ] dx
=[ arctanx + (1/4)Cx^4]|(0->1)
= π/4 + (1/4)C