i got some probs. to solve this integrals :

integral x*arctan(x)dx

integral (11x+7)/(2x^2+7x-4)dx

integral ln(x^2+1)dx

intgral e^x/(1-e^3x)dx

i tryed solving this but i get stucked somewhere the first one is with partial integration ,second one i substitute the denominator with u and i get 4x+7 for du and there i get stucked ,the third one is partial as well but again as the first one i get to a point where i need to solve integral x^2/(x^2+1) and this one is not rly simple i dont know to solve it so i need help there, the 4 one is also with sub. for u=e^x but then i get integral 1/1-u^3 i tryed to make sub. for t=1-u^3 so i can get one parameter in the denominator and two up and than devide in two integrals but i couldnt get it.. please some help if you know how to solve this , btw these are from faculty from exam sessions thanks!