# Sum Rule

## Reference > Calculus: Differentiation

 Description$\frac{d}{dx} f(x)+g(x)=(\frac{d}{dx} f(x))+(\frac{d}{dx} g(x))$
 Examples$\frac{d}{dx} \cos{x}+\sin{x}$1 Apply the Sum Rule: $$\frac{d}{dx} f(x)+g(x)=(\frac{d}{dx} f(x))+(\frac{d}{dx} g(x))$$$(\frac{d}{dx} \cos{x})+(\frac{d}{dx} \sin{x})$2 The derivative of $$\cos{x}$$ is $$-\sin{x}$$$-\sin{x}+(\frac{d}{dx} \sin{x})$3 The derivative of $$\sin{x}$$ is $$\cos{x}$$$\cos{x}-\sin{x}$Donecos(x)-sin(x)