# Problem of the Week

## Updated at Nov 11, 2013 9:46 AM

For this week we've brought you this calculus problem.

How would you differentiate $$\sec^{3}x$$?

Here are the steps:

$\frac{d}{dx} \sec^{3}x$

 1 Use Chain Rule on $$\frac{d}{dx} \sec^{3}x$$. Let $$u=\sec{x}$$. Use Power Rule: $$\frac{d}{du} {u}^{n}=n{u}^{n-1}$$.$3\sec^{2}x(\frac{d}{dx} \sec{x})$2 Use Trigonometric Differentiation: the derivative of $$\sec{x}$$ is $$\sec{x}\tan{x}$$.$3\sec^{3}x\tan{x}$Done3*sec(x)^3*tan(x)