Sum Rule

Reference > Calculus: Differentiation

Description
ddxf(x)+g(x)=(ddxf(x))+(ddxg(x))\frac{d}{dx} f(x)+g(x)=(\frac{d}{dx} f(x))+(\frac{d}{dx} g(x))
Examples
ddxcosx+sinx\frac{d}{dx} \cos{x}+\sin{x}
1
Use Sum Rule: ddxf(x)+g(x)=(ddxf(x))+(ddxg(x))\frac{d}{dx} f(x)+g(x)=(\frac{d}{dx} f(x))+(\frac{d}{dx} g(x)).
(ddxcosx)+(ddxsinx)(\frac{d}{dx} \cos{x})+(\frac{d}{dx} \sin{x})

2
Use Trigonometric Differentiation: the derivative of cosx\cos{x} is sinx-\sin{x}.
sinx+(ddxsinx)-\sin{x}+(\frac{d}{dx} \sin{x})

3
Use Trigonometric Differentiation: the derivative of sinx\sin{x} is cosx\cos{x}.
cosxsinx\cos{x}-\sin{x}

Done