In mathematics, an algebraic function is a function that satisfies a polynomial equation. Thus an equation of the following form holds: where the are polynomials. Basic examples of algebraic functions are polynomial functions, rational functions, the nth root function, and functions obtained from these by composition and algebraic operations. Thus an example of an algebraic function is the function , whose graph is the top half of the standard unit circle. This function satisfies . Algebraic functions are contrasted with transcendental functions, such as the exponential function, logarithm, and the trigonometric functions.