u=2x;
du=2dx
dx=(1/2)du=(1/2)d(2x)
=(1/2)e^(2x)|^(3)_(0)=(1/2)*(e^(6)-e^(0))=(1/2)*(e^(6)-1)
2)= (1/3) arctg(x/3)|^(3)_(0)=(1/3)(arctg1-arctg0)=(1/3)*((π/4)-0)=π/12
3)=((x^3/3)-2*(x^2/2)+3x)|^(2)_(1)=
=((2^3/3)-2*(2^2/2)+3*2)-((1^3/3)-2*(1^2/2)+3*1)=7/3