# Product Rule

## Reference > Calculus: Differentiation

 Description$(fg)'=f'g+fg'$
 Examples$\frac{d}{dx} \sin{x}{x}^{2}$1 Regroup terms.$\frac{d}{dx} {x}^{2}\sin{x}$2 Use Product Rule to find the derivative of $${x}^{2}\sin{x}$$. The product rule states that $$(fg)'=f'g+fg'$$.$(\frac{d}{dx} {x}^{2})\sin{x}+{x}^{2}(\frac{d}{dx} \sin{x})$3 Use Power Rule: $$\frac{d}{dx} {x}^{n}=n{x}^{n-1}$$.$2x\sin{x}+{x}^{2}(\frac{d}{dx} \sin{x})$4 Use Trigonometric Differentiation: the derivative of $$\sin{x}$$ is $$\cos{x}$$.$2x\sin{x}+{x}^{2}\cos{x}$Done2*x*sin(x)+x^2*cos(x)