Can anyone help me integrate this: integral of

Question

1.) (3x+in2x)^3/x dx,

2.) x^2in^3(1+x^3)/1+x^3 dx,

3.) v(v^2-1)/v^2+1 dv,

4.)e^2x(1+e^2x)^3dx?

Answer 1

3.

The function is

 

Answer 2

1.

The function is 

Answer 3

4.

The integral is