When considering the common logarithm (i.e., base 10), we notice that as the
values decrease from 1 to 0, the curve falls rapidly, and for
, it approaches the negative
axis asymptotically. As the
values increase from 1 to 10, the function increases monotonically from 0 to 1, and as
values increase by a factor of 10 (for example, from 10 to 100) the function increases from 1 to 2. The same applies for the intervals
, and so on. Because the changes are very small for such large intervals, the curve can be well approximated by a straight line.