From Encyclopediaofmath The function $y=e^x$, also denoted by $y=\exp x$. Sometimes the function $y=a^x$ for any base $a>0$ is also called an exponential function.
See also Exponential function; Exponent; $e$ (number). The inverse of the exponential function is the logarithmic function (cf. also Logarithm of a number). The value of the exponential function at a point is also called the antilogarithm of this point.