Originally Posted by
Jhevon so there are two ways to go here. it is mainly a matter of personal preference. i am the kind of guy that, unless it causes way too much trouble, leaves the limits in tact in terms of x. when i integrate in terms of u i just rewrite the answer in terms of x and use the old limits
the other option is to change the limits so that you can use them with u. in that case, you use your substitution equation.
we have u = x - 3
so when x = 0, u = -3
when x = 2, u = 1
so your limits in u is from -3 up to 1, not 0 up to 2