in the interval [x,x+h]
Avg. rate of change = (f(x+h)-f(x))/(x+h-x)\
= (tan(x+h) - tan(x))/h
I need this to equal (tanh/h)*((sec^2(x))/(1-tanxtanh))
I'm thinking tan addition forumula...
I tried common denominator on the top, factoring out a tanh, but I'm going in circles. Please help.