log10, log10f---base 10 logarithms#include <math.h> double log10(double x); float log10f(float x);Description
log10 returns the base 10 logarithm of x.
It is implemented as log(x) / log(10).
log10f is identical, save that it takes and returns float values.
Returns
log10 and log10f return the calculated value.
See the description of log for information on errors.
Portability
log10 is ANSI C. log10f is an extension.