I've got a graph image, but I need the formula used the create this graph. This image is being used to read the result corresponding values manually, but I want to automate this by using a formula.
The X axis is a known value 'som van de faktoren', the Y axis 'tijd in jaren' should be the resulting value.
The only value that is 100% sure is 0 (x) = 15 (y). However, as you can see 5 (x) = 12 (y) should be 99% correct too.
Is it possible to connect a formula based on the visual graph? I'm both curious for the formula as for the way of resolving it :-)
I'm not allowed to post images yet, so here is a url to the graph; https://www.dropbox.com/s/5u2vq6i5s0ld84x/Screenshot%25202015-07-13%252012.57.56.png?dl=0
The graph looks like a graph of an exponential function: $y=a\cdot e^{-bx}$
You have identified two points: $P_1(0/15)$ and $P_2(5/12)$. You can insert the values and you get two equations:
$15=a\cdot e^{-b\cdot 0}$
$12=a\cdot e^{-b\cdot 5}$
The first equation becomes $15=a\cdot 1$. Now you can insert the value of a in the second equation and calculate the value of b.
The graph with the values of a and b looks like