# Question #d0c3c

##### 1 Answer

Sep 27, 2017

-sin x

#### Explanation:

Sin x and cos x work as thus.

If

In other words, every 4thmderivative is the original function, as is the eighth, the twelfth, etc. (Note that if we have

The highest multiple of 4 in our exponent is 84, so we can essentially ignore that part for the derivative.