Question

积分号（2x^4）／（1+x^2）dx

Answer 1

∫(2x^4)/(1+x^2) dx

=2∫x^4/(1+x^2) dx

=2∫ [x^2+1/(1+x^2)-1] dx

=2[(x^3)/3+arctanx-x]+C

=2/3·x^3+2arctanx-2x+C