Problem of the Week

Updated at Sep 14, 2015 2:16 PM

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

How would you differentiate secx+sinx\sec{x}+\sin{x}?

Here are the steps:



ddxsecx+sinx\frac{d}{dx} \sec{x}+\sin{x}

1
Use Sum Rule: ddxf(x)+g(x)=(ddxf(x))+(ddxg(x))\frac{d}{dx} f(x)+g(x)=(\frac{d}{dx} f(x))+(\frac{d}{dx} g(x)).
(ddxsecx)+(ddxsinx)(\frac{d}{dx} \sec{x})+(\frac{d}{dx} \sin{x})

2
Use Trigonometric Differentiation: the derivative of secx\sec{x} is secxtanx\sec{x}\tan{x}.
secxtanx+(ddxsinx)\sec{x}\tan{x}+(\frac{d}{dx} \sin{x})

3
Use Trigonometric Differentiation: the derivative of sinx\sin{x} is cosx\cos{x}.
secxtanx+cosx\sec{x}\tan{x}+\cos{x}

Done