Here's the limit that I need to calculate :

lim x→y (x/x-y)*∫f(t)dt

where y is a real constant and f(t) is a continuous function. The integral is defined between y and x.

I haven't calculated limits for a while now, so I don't even know where to start. If someone could help me, that would be appreciated.

P.S. I don't need the answer, just a starting point