So the question is:

If f(x) is the slope of a walking track at a distance of x kilometres from the start of the track, what does

$\displaystyle \int_3^5f(x)dx $ represent?

So, yeah, Im confused as to what the answer is. Solving that out would give a value right. And the value would be the area under the curve. Is it something to do with the total change of the slope from 3km from the start to 5km? Or am I completely off?

I'm sure this is really simple, but nonetheless, I am more lost than the people on the show LOST.