Since I didn't know how to integrate or differentiate most of the functions, my main focus was on key events in the graph. I decided the two events worth focusing on were stationery points and where the graph meets the x axis. This was because I realised that a stationery point on an integral had a gradient of 0 and therefore the differential cut through the x axis at that point. Looking at it the other way round, the area of the differential does not change at all when it is touching the x axis, so there is a stationery point on the integral.
I wrote down the x coordinates for the stationery points and x intercepts and after that it was quite easy to match them up (differentials on the left):
J A
C L
K F
G E
I H
D B
As for the functions used:
Chart A: y=x
Chart B: based on a cubic curve?
Chart C: based on an exponencial curve with a base between 0 and 1?
Chart D: based on a cubic curve?
Chart E: not sure
Chart F: y=sin(x) (in radians)
Chart G: y=-1/2cos(2x)+0.5 (in radians)(for example)
Chart H: similar to Chart C shifted upwards
Chart I: not sure
Chart J: y=1
Chart K: y=cos(x) (in radians)
Chart L: not sure, some sort of polinomial?