Only a function that actually shows the word "ln" or "log" or "log to the base b" is a log function.
Taking a closer look at #3: y = log 0.25^x, we see that this can be simplified by writing the base (10) as follows: 10 10
and then using y as the exponent of the first 10 and log 0.25^x as the exponent of the second 10:
10^y = 10^(log 0.25^x)
You were not asked to do this, but this discussion may be of interest and help to you down the line.
10^y = 0.25^x
