# Wrapping It Up

- Author:
- Allen Olson

So there are many ways to look at a simple formula like Ohm's law. Even though there are only three quantities involved, there are six different graphs that can be plotted:

- Current as a function of voltage
- Current as a function of resistance
- Voltage as a function of current
- Voltage as a function of resistance
- Resistance as a function of voltage
- Resistance as a function of current

## Which of these are linear?

(*Select more than one answer!*)

For Ohm's law, the main feature of the formula is proportionality. Even when the graph is non-linear, it is a proportional relationship... we just call it "inversely proportional." When the input is multiplied by a certain factor, the output is divided by that same factor... when the resistance is doubled, the current is cut in half (assuming the voltage remains constant).