# Homework Help: Derivative of 10 - 20/(t+1)^2 - process help

1. Feb 13, 2012

### 939

1. The problem statement, all variables and given/known data

Derivative of

10 - 20/(t+1)^2. It's hard to write but basically 10 is IN FRONT of the equation, it's NOT 10-20 together, over (t+1)^2. 10 is seperate and is in front of the equation.

2. Relevant equations

10 - 20/(t+1)^2

3. The attempt at a solution

My main question is the process. Do you find the derivative of - 20/(t+1)^2, and then put 10 in front of the equation? Or do you multiply the derivative of it by 10?

2. Feb 13, 2012

### eumyang

First, what you wrote is not an equation. It's an expression.
Do you mean this?
$$f(x) = 10 - \frac{20}{(t+1)^2}$$
If you mean the above, then no. You find the derivative of 10, and then subtract the derivative of the fraction. The difference rule applies (derivative of f - g = f' - g').

EDIT: Or do you mean this?
$$f(x) = 10\frac{-20}{(t+1)^2}$$

3. Feb 13, 2012

### 939

Thanks a lot for the help. And I meant this one.