# Problem of the Week

## Updated at Jun 30, 2014 8:59 AM

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

How can we solve for the derivative of $$9\tan{x}$$?

Check out the solution below!

$\frac{d}{dx} 9\tan{x}$

 1 Use Constant Factor Rule: $$\frac{d}{dx} cf(x)=c(\frac{d}{dx} f(x))$$.$9(\frac{d}{dx} \tan{x})$2 Use Trigonometric Differentiation: the derivative of $$\tan{x}$$ is $$\sec^{2}x$$.$9\sec^{2}x$Done9*sec(x)^2