(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Find dy/dx for the following function:

y = (11-cos(x))/(2+cos(x))

2. Relevant equations

Quotient Rule:

y'= ((g(x))(f'(x)) - (f(x))(g'(x)))/ (g(x)^2)

3. The attempt at a solution

I used the quotient rule to come up with this:

y'= ((2+cos(x))(sin(x)) - (11-cos(x))(-sin(x))) / ((2+cos(x))^2)

Now, the trouble that I am having is simplifying this.

The final answer should turn out to be :

(13sin(x))/(cos(x)+2)^2

I am overlooking some basic arithmetic here, but I can't seem to find out what I am missing. Am I supposed to multiply out the expressions first and then combine like terms? Basically, how do I go from the expanded version to the simplified version? Thank you

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Arithmetic Question for Finding Derivative using Quotient Rule

**Physics Forums | Science Articles, Homework Help, Discussion**