# Evaluating Functions

1. Sep 15, 2011

### ninjamonke

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

[PLAIN]http://img89.imageshack.us/img89/6410/c3602011091514253311.jpg [Broken]

2. Relevant equations

Both a and b.

3. The attempt at a solution

For problem a, I don't know what to after that. If you could direct/tell me what to do next, I'd be able to figure it out.
For problem b, I don't know how to set it up.

Last edited by a moderator: May 5, 2017
2. Sep 15, 2011

### A_B

For a. , try getting rid of some denominators, it comes out very nicely.
For b. Do exactly what you did for a. Only now because you have the function F() in the expression multiple times, so you'll have to do the substitution multiple times.

Hope this helps enough.. but not too much.

3. Sep 15, 2011

### ninjamonke

For a, do I multiply everything on the bottom by y?

4. Sep 15, 2011

### HallsofIvy

Staff Emeritus
Yes, multiply both numerator and denominator by y.

5. Sep 15, 2011

### ninjamonke

This is my answer that I got.

[PLAIN]http://img838.imageshack.us/img838/1974/c36020110915181646.jpg [Broken]

Is it right?

I did that but I don't know if I did it correctly.

[PLAIN]http://img269.imageshack.us/img269/8973/c360201109151748431.jpg [Broken]

Last edited by a moderator: May 5, 2017
6. Sep 16, 2011

### J2R

I re-wrote the denominator like this:

3y+4/y - 3/1

From here I just cross multiplied:

3y + 4 - 3y

Combine like terms and you end up with 4/4.

F(3y+4/y) = 1

7. Sep 16, 2011