An exponential function is a function of the form
f(x) = a^x (2³ = 2 * 2 * 2 = 8)
where a is a fixed, positive constant, called the base of the exponential function.
Exponential functions are used to express dynamic processes, also in diagnostic imaging procedures.

Conversion of the analog signal to a series of digital values by measurement at a set of particular times; this utilizes the analog to digital converter. If the rate of sampling is less than twice the highest frequency in the signal, aliasing will occur. The duration of sampling determines how small a difference of frequencies can be separated.

See also Algorithm, Trigonometric Functions, Digitization, Exponential Functions, Imaginary Number, Logarithms, Point Spread Function.