I want the 1st, 2nd and 3rd derivatives of the following seven parameter double sigmoid function
Y = a + b /(1 + exp(-c(X-d))) – e/(1 + exp(-f(X-g)))
a,b,c,d,e,f,g are the equation parameters.
I can go as far as the 1st derivative:
If z = (1 + exp(-c(X-d))) and h = (1 + exp(-f(X-g)))...