# Chain Rule

## Reference > Calculus: Differentiation

 Description$\frac{dy}{dx}=\frac{dy}{du}\times \frac{du}{dx}$
 Examples$\frac{d}{dx} \sin{(\ln{x})}$1 Use Chain Rule on $$\frac{d}{dx} \sin{(\ln{x})}$$. Let $$u=\ln{x}$$The derivative of $$\sin{u}$$ is $$\cos{u}$$$\cos{(\ln{x})}(\frac{d}{dx} \ln{x})$2 The derivative of $$\ln{x}$$ is $$\frac{1}{x}$$$\frac{\cos{(\ln{x})}}{x}$Donecos(ln(x))/x