Chain Rule (Edexcel A-Level Mathematics): Flashcards

Technique to differentiate composite functions.

$dy/dx = f'(g(x)) * g'(x)$

$f'(g(x))$ is the derivative of the outer function.

$g'(x)$ is the derivative of the inner function.

$\frac{dy}{dx} = \frac{dy}{du} \cdot \frac{du}{dx}$

Identify the outer and inner functions.

The derivative is $n \cdot x^{(n-1)}$.

Multiply the derivatives of outer and inner functions.

$\frac{dy}{dx} = 3\cos(3x)$

$\frac{dy}{dx} = \frac{10x}{5x^2 + 1}$