Product Rule — SFI App

The three-dimensional construction needs WebGL 2. The rectangle remains fully interactive.

A = fg

Choose each function

x 1.20 Δx 0.30

Current product A = f(x) · g(x) Exact finite change

First-order contribution

Derivative as Δx → 0

Each first-order strip is swept out by one changing dimension while the other supplies its instantaneous length.