Say I have a line integral which I have simplified to:
[itex]\int\int x+y dS[/itex]
Over some surface S, let's say 5x^2 + 3y^2 = 4 or something. Having arrived at this step, how do I determine dS? The formulas and methods we've been taught doesn't really lead to this step all that often but I'd like to know a general approach for determining dS when it is in this form.