My question involves the u-substitution rule for calculus. I do not understand it intuitively, and am relying purely on a mechanical recital, so I do not understand what happens to the "du"?
here is an example of my confusion:
= (x^2)/2 + C
so I set and .
But where does the "du" go? It always seems to disappear, but I am not good enough at mathematics to understand why.
Thanks for your input.