C Programming/math.h/log

Logarithmic function in 'c' language
these functions are under math.h. In general log(x) i.e ln(x) and log10(x) these are two types of logarithm.In C language function is available for both of these. so that we can use mathematical terms effectively. log(x) is natural logarithm. log10 is base 10.

return value
return the natural logarithm of x. The natural logarithm is the base-e logarithm, the inverse of the natural exponential function.

Return value'
compute common logarithm and return the common(base - 10) logarithm of x, where x>0.