# Cuse these difference quotients

1. Aug 29, 2008

### leftyguitarjo

Cuse these difference quotients!!!

1. The problem statement, all variables and given/known data
http://www.webassign.net/www14/symImages/5/8/30f1e141e81c6a3333af41547f8ff2.gif

Evaluate the difference quotient for the given function

http://www.webassign.net/www14/symImages/4/6/bda668fa415dbf5d0c9c2ba4c031d2.gif

2. Relevant equations
n/a

3. The attempt at a solution
I seem to have the wrong mindset while doing these.

I got 0.

Actually, I dont really know exactly what I'm even going for here.

Last edited by a moderator: Apr 23, 2017
2. Aug 29, 2008

### Dick

Re: Cuse these difference quotients!!!

It's not zero. It's a function of x. Why don't you show us what you did? Just substitute the given f(x) into the difference quotient.

3. Aug 29, 2008

### leftyguitarjo

Re: Cuse these difference quotients!!!

My main thing is that I dont know what the outcome should look like.

It was during the last few weeks of my senior year of high school so I didnt exactly make it to class every day and I missed this stuff. Its coming back to bite me in college now.

4. Aug 29, 2008

### Dick

Re: Cuse these difference quotients!!!

I told you, just substitute the form for f(x) into the difference quotient and try and do some algebra to simplify it. What is f(5)? This isn't a big conceptual problem.

5. Aug 29, 2008

### sutupidmath

Re: Cuse these difference quotients!!!

Later on you will see that the slope of the tangent line at a point say P(a,f(a)), is given by:

$$\lim_{x\rightarrow a}\frac{f(x)-f(a)}{x-a}=f'(a)$$

And only the quotient $$\frac{f(x)-f(a)}{x-a}$$ is the slope of secat line.

So, you are given a function f(x) and then asked to find the quotient.

$$\frac{f(x)-f(5)}{x-5}$$ so what u want to do is replace f(x) with what you are given, in other words, write the function f(x)=... whatever it equals, and then for f(5), you first want to evalulate f(5)=...whatever it equals. You evaluate f(5) by plugging 5 in

$$f(x)=\frac{x+7}{x+5}$$

Last edited by a moderator: Apr 23, 2017
6. Aug 29, 2008

### HallsofIvy

Staff Emeritus
Re: Cuse these difference quotients!!!

Dick said "Why don't you show us what you did? " Why will you not do that?