The C library function double log(double x) returns the natural logarithm (base-e logarithm) of x.
double log(double x)
#include #include int main () { double x, ret; x = 2.7; /* finding log(2.7) */ ret = log(x); printf("log(%lf) = %lf", x, ret); return(0); }
log(2.700000) = 0.993252