# Problem of the Week

## Updated at Oct 13, 2014 4:29 PM

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

How can we solve for the derivative of $$3x-\tan{x}$$?

Check out the solution below!

$\frac{d}{dx} 3x-\tan{x}$

 1 Use Sum Rule: $$\frac{d}{dx} f(x)+g(x)=(\frac{d}{dx} f(x))+(\frac{d}{dx} g(x))$$.$(\frac{d}{dx} 3x)-(\frac{d}{dx} \tan{x})$2 Use Power Rule: $$\frac{d}{dx} {x}^{n}=n{x}^{n-1}$$.$3-(\frac{d}{dx} \tan{x})$3 Use Trigonometric Differentiation: the derivative of $$\tan{x}$$ is $$\sec^{2}x$$.$3-\sec^{2}x$Done3-sec(x)^2