1. The problem statement, all variables and given/known data This is an example problem from my stewart calculus book. the whole problem is "solve this diff eq: y' + 3(x^2)y = 6x^2 next step is to find I(x) which is e^(x^3) and multiply everything by that then you say (I(x)y)' = 6(x^2)(e^(x^3)) and then you integrate both sides so I(x)y = the integral of [6(x^2)(e^(x^3))]. this is where i have problems. i cannot figure out the integral on the right hand side. the book then shows the answer to the integral as 2e^(x^3) + C and the final answer is then y = Ce^(-x^3) Also if someone could explain to me why the final answer has the negative sign in the exponent that would be helpful. Ive looked at the problem for a while so maybe im doing something wrong or there is a trick im missing but ive tried to do it "by parts" with no luck. I was under the impression that you cannot just take the integral of an exponential like e^x^x.