How to evaluate this integration
f(x) = 2x , x<=1
f(x) - 2, x>1
$\displaystyle \int_{1}^{5} f(x) dx $
thanx..
If your problem is written correctly, you are really only dealing with one function; look at your limits of integration - it starts off at 1, and your two functions are actually "split" at x=1. The only function that we care about is F(x)=2 (or is that -2?). This one should be pretty easy to do without even using calculus (although you should, just to show that you know how to get the right answer).