1. The problem statement, all variables and given/known data I have given two graphs which i try to show in the picture here. The question in to find u'(1) and v'(5) 2. Relevant equations So the relevant equations here are the Product Rule and the Quotient Rule, which I know and is not the big problem here. I think (but imnot sure) the issue here is to find the primitive functions. But these graphs change ???? For example the function f(x) has 3 different equations IMHO see x=-2 till 0 and x=0 till 2 and x=2 till 7 (at least thats what visible on the given graph) 3. The attempt at a solution Well I could determine the slopes and create 3 linear functions for f and two linear functions for g. the slope for f(x) in interval x = 0 till 2: m = (4-0)/ (2-0) = 2 y(2) = 2*2 + b = 4 b = 0 So I can say that f = 2x+0, All great but i think im completely lost. Main thing I dont understand the question? The derivative is the slope (right?), but if I don't have the functions how can I determine the slope, well I just did that so what should I do now. Or is my answer m= 2 basically u'(1)? This seems like but it would also be for u'(1.5). Can anybody tell me where I miss the point? And next when would this happen in a practically situation? I like to connect the things to real life situations. Thanks in advance and apologizes if someone can't understand my confusion. I have calculus on school but they try to teach me everything with about 50 exercises so I bought A big calculus book and doing the exercises alone as I'm doing distance learning no teachers around.