# Problem of the Week

## Updated at Jun 1, 2015 8:09 AM

To get more practice in calculus, we brought you this problem of the week:

How can we find the derivative of $$7x-\sin{x}$$?

Check out the solution below!

$\frac{d}{dx} 7x-\sin{x}$

 1 Use Sum Rule: $$\frac{d}{dx} f(x)+g(x)=(\frac{d}{dx} f(x))+(\frac{d}{dx} g(x))$$.$(\frac{d}{dx} 7x)-(\frac{d}{dx} \sin{x})$2 Use Power Rule: $$\frac{d}{dx} {x}^{n}=n{x}^{n-1}$$.$7-(\frac{d}{dx} \sin{x})$3 Use Trigonometric Differentiation: the derivative of $$\sin{x}$$ is $$\cos{x}$$.$7-\cos{x}$Done7-cos(x)