Problem of the Week

Updated at May 12, 2014 11:49 AM

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

How would you differentiate \(\cos{x}-4x\)?

Check out the solution below!



\[\frac{d}{dx} \cos{x}-4x\]

1
Use Sum Rule: \(\frac{d}{dx} f(x)+g(x)=(\frac{d}{dx} f(x))+(\frac{d}{dx} g(x))\).
\[(\frac{d}{dx} \cos{x})+(\frac{d}{dx} -4x)\]

2
Use Trigonometric Differentiation: the derivative of \(\cos{x}\) is \(-\sin{x}\).
\[-\sin{x}+(\frac{d}{dx} -4x)\]

3
Use Power Rule: \(\frac{d}{dx} {x}^{n}=n{x}^{n-1}\).
\[-\sin{x}-4\]

Done
Cymath foriOSAndroid