Logarithmic function is a function with power as independent variable, exponent as dependent variable and base constant. It is one of the six basic functions. If a x = n, the number x is called the logarithm of the base of n, denoted as x=logaN, and read as the logarithm of the base of n, where a is called the base of logarithm and n is called a real number. Generally speaking, the function y=logaX is called logarithmic function, where "log" is the abbreviation of Latin logarithm.