integrate:

1. 1/ x^2* sqr(x^2+4) dx sqr is square root

2. e^(2x)*sin(e^x)dx ( I know I should do by parts but I am stucked)

3. 1/ sqr(x)*(x^(1/3)+1)dx

4. x^(2)+1 / (x^(3)-4x^2)dx

5. 1/ (x* sqr(9+4*x^(2)))dx

6.x^(2)/ sqr(2x-x^(2)) dx

7. cost / (2 -(sint)^(2)) dt ( I guess it's an exact derivative here but I can't move on)

8. x^(3)/ (a^(2)-x^2) dx I can't move on with trig substitution

9. lnx / (x+1)^2 dx

10. e^(ax) * cos(bx) dx By Parts ? how can I do it ?

11. x* e^(sqr(x))dx

12. Arctan (sqr(x)) dx

13. (tan(x))^6 dx

14. (sec(x))^6dx

15. x^(1/3) / (1+x) dx

Some more to come !!

Please give me some help. I really need it.