[2]
“There are many applications of exponential functions and logarithmic functions in science and technology. The voltage in a given circuit can be expressed using exponents. The value of money in an investment can be determined through the use of exponents. The intensity of earthquakes is measured by a logarithmic scale. The intensity of light related to the thickness of the material through which it passes can be expressed using exponents. The distinction between acids and bases in chemistry is measured in terms of logarithms.” [3]
When it comes to exponential functions, the word exponent is often used instead of index, and functions in which the variable is in the index (such as 2x, 10sinx) are called exponential functions. [4] If b is a real number greater than zero, then for each real exponent x we assume bx is a unique real number. Since for each real x there is one and only one bx, the equation y=bx,(b>0)
defines a function. We call such an equation an exponential function.