Hi,I'm new to mathhelpforum.

This problem comes from Calculus vol 1 by Richard Silverman.

Why this proof of Couchy's theorm isn't correct?

If

f'(c)=(f(b)-f(a))/(b-a)

and

g'(c)=(g(b)-g(a))/(b-a)

Then by dividing f'(c) to g'(c) :

f'(c)/g'(c)=(f(b)-f(a))/(g(b)-g(a))