Please watch this 17min video by the very good math YouTube channel/website 3blue1brown. We will discuss this video (and subsequent videos in this series) in class:
Here is the next video in his “Essence of Calculus” series, which discusses derivatives (and specifically the Power Rule for derivatives of power functions f(x) = x^n) geometrically:
Updated this post with the next video in 3blue1brown’s “Essence of Calculus” series (“Geometric derivatives”)