We introduce Rolle's theorem which we will later use in a proof of the Mean Value theorem. Rolle's theorem states that if a function is continuous on [a,b] and differentiable on (a,b), and f(a)=f(b), then there exists a point c in (a,b) so that f'(c)=0, that is - a place where the derivative is 0. We'll prove Rolle's theorem and go through two examples of using Rolle's theorem. In the first example we will find two x-intercepts of our function then use Rolle's theorem, and in the other example we will use Rolle's theorem to prove a cubic has only one root. #calculus1 #apcalculus Join Wrath of Math to get exclusive videos, lecture notes, and more: Calculus 1 Exercises playlist: Calculus 1 playlist: Get the textbook for this course! 0:00 Intro 0:15 Rolle's Theorem 1:00 Rolle's Theorem Visualized 2:27 Proof of Rolle's Theorem 5:33 Example 1 of using Rolle's Theorem 7:30 Example 2 of using Rolle's Theorem 10:25 Conclusion ★DONATE★ ◆ Support Wrath of Math on Patreon: ◆ Donate on PayPal: Outro music by Ben Watts and is available for channel members. Follow Wrath of Math on... ● Instagram: ● TikTok: @wrathofmathedu ● X: ● Facebook: