# Graphing Thin Lens Equation

1. Jan 18, 2008

### Larrytsai

I need to learn how to graph do=1/(f -1/di) like i have my measurements and when i plug in my di i get a do so what do i do with my old do?

2. Jan 19, 2008

### Tom Mattson

Staff Emeritus
Are you sure that's the correct equation? Shouldn't it be the following?

$$d_o=\frac{fd_i}{d_i-f}$$

3. Jan 19, 2008

### Larrytsai

umm thats the way my teacher wrote it. Iduno he might be wrong lol

4. Jan 26, 2008

### Tom Mattson

Staff Emeritus
I don't think you typed it in correctly. In the denominator you have f-1/di. You're subtracting a distance and an inverse distance. The units don't work out. Please check it. Also, when you say you need to graph the equation, do you know the values of any of the variables do, di, or f? If not, then you'll have to do a 3D graph, which is much more involved.