Lili Barua on Instagram: "Mastering the limit definition of the derivative is a non-negotiable for a high score on the AP Calculus AB/BC and the JEE Main & Advanced exams. This animation provides the foundational geometric proof needed to build deep intuition for differential calculus. We start with the average rate of change, represented by a secant line cutting through two points on a function’s graph—a core concept from high school algebra. The true power of calculus is revealed when we apply