I am missing something in my substitution of integrals. For example:
Integral of 5x^2cos(x^3)dx
u=x^3 du=3x^2dx x^2dx=1/3du.
I don't understand where you get the 1/3du.

Question

I am missing something in my substitution of integrals. For example:
Integral of  5x^2cos(x^3)dx
u=x^3 du=3x^2dx  x^2dx=1/3du.
I don't understand where you get the 1/3du.

anonymous · Answer

$$u=x ^{3}   =  du/dx=3x ^{2}  =  du/3=x ^{2}dx$$
You move the 3 from the right side of the equation to the left hand by dividing with 1/3.
You're then left with du/3 = x^2dx

anonymous · Answer

If you dont understand what I meant, I'll try to explain further. :)

anonymous · Answer

Thanks I appreciate that!

anonymous · Answer

Good, glad I could help.