Integration Problems

[king123]

Hey guys, I could use some help with these problems:

(I don't know how to get any of the symbols so bear with me)

 

integral from 0 to pi/4 of cos^4(4x)sin(4x)dx

 

integral(x^3-5x+2)/(x^2+49)dx

 

integral 2x^3squareroot(25+36x^2)dx

 

integral sin^2(5x)cos^5(5x)dx

 

integral sin^2(6x)cos^2(6x)dx

 

Any kind of help and/or solutions would be appreciated here.

[ecoli]

do you know how to do u-substitution (change of variables)?