7.1 The product rule for derivatives

$$\frac{d}{dx} \left(f(x) \times g(x)\right) = \frac{df}{dx}g(x) + f(x)\frac{dg}{dx}.$$

Example:

$$\frac{d}{dx}\left(x^2 \times x^3\right) = 2\,x \, x^3 + x^2\,3\,x^2 = 5\,x^4.$$