Answer
We use the concept of total differential to estimate the change in productivity for a small change in both labor and capital. The differential for a function of one variable $y=f(x)$ is used to approximate the function by its tangent line. The differential for a function of two variables $z=f(x,y)$ is used to approximate a function by its tangent plane.
Work Step by Step
We use the concept of total differential to estimate the change in productivity for a small change in both labor and capital. The differential for a function of one variable $y=f(x)$ is used to approximate the function by its tangent line. The differential for a function of two variables $z=f(x,y)$ is used to approximate a function by its tangent plane.
