Equation of a Tangent Line, Taking Derivatives, Differential Calculus

Using a specific example, Sal shows how to find the equation of a tangent line to a given function at a specific point. Specifically, he solves the problem of finding the tangent line to the function f(x) = xex at x = 1. This problem provides a review of the product rule, the slope-intercept form of a line, and the steps for finding the equation of a line. It also provides a pleasant visual understanding of the problem by graphing both the original equation and the found tangent line.