# Problem of the Week

## Updated at Jul 27, 2020 1:28 PM

This week we have another calculus problem:

How would you differentiate $$\cot{u}+\tan{u}$$?

Let's start!

$\frac{d}{du} \cot{u}+\tan{u}$

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