This is probably more of a maths question than a programming one, but I can't find a more suitable category.
I'm drawing best fit lines on graphs, and using the information here:
That page shows how to calculate the variables for the following lines:
y = a + bx
y = a + bx + cx^2
I've implemented them, and everything works fine. However, now I nee to do the same thing for these lines:
y = a + bx + cx^2 + dx^3
y = a + bx + cx^2 + dx^3 + ex^4
y = ab^x
But I can't find similar equations for calculating the replacements for a-e in those equations. I've found some stuff on the web, but nothing in that kind of format (the "first format" shown - which I can understand, and implement!).
Does anyone know how to calculate these?