multivar integration basic q
write an iterated integral for 4R dA over the
described region R using (a) vertical cross-sections, (b) horizontal
cross-sections.
Bounded by y = 0, x = 0, y = 1, and y = ln x
I've given the question and the solution.
What I don't understand is why we need to take 2 multiple integrals for vertical cross section and only 1 for horizontal? how do I tell where do draw the limits I'm very confused