Rolle's Theorem which is a special case of the mean-value theorem states that:
if a function " f " is
- Continuous on the closed interval [a, b]
- Differentiable on the open interval ]a, b[
- f(a) = f(b)
then, there is at least one value c ∊ ]a, b[ that:
f′(c) = 0
How can we find the value of "c"?
- We make sure that the function " f " satisfies the conditions of Rolle's theorem
- We find f′(x) (The derivative with respect to "x")
- We put f′(c) (We replace the "x" in the derivative with "c")
- We put f′(c) = 0
- Finally, we find the value of "c"