find the extreme values of the function on the interval and where they occur.

f(x) = |x-1|-|x-5|, -2<=x<=7

How do I do this? Sorry for double post. I really need to do this,

I don't see an easy way. You can graph it, there is not anything here that would take long to graph. graph at -2, 0, 1, 5, 7

Don't I have to take derivative of f(x)?

I don't think you will get a maxima, what you will get will be extremes at some of the critical points on the graph. Taking the derivatives on a linear function with abs doesn't reveal much.

graph it.

OK please tell me how to solve this.

find the extreme values of this function on the interval and where they occur.
f(x) = abs(x+2)-abs(x-3), -infinity<x<infinity

Thank you.