We could take some typical values and join the dots to graph the log function, as follows:

x `0.01` `0.1` `0.5` `1` `2` `3` `4`
f(x) `-2` `-1` `-0.30` `0` `0.30` `0.48` `0.60`
12341-1-2-3-4xyOpen image in a new page

Graph of `y=log_10 x`.

Notice that we cannot take zero or negative values for x. Can you figure out why not?

Our curve passes through `(1, 0)` (on the x-axis).

Easy to understand math videos:
MathTutorDVD.com