Algebraic number

An algebraic number is any real number that is a solution of some one-variable polynomial equation whose coefficients are all integers. All rational numbers are algebraic numbers, along with some irrational numbers. For example, the golden ratio formula_1 is a solution to the equation formula_2. A real number that is not algebraic is called transcendental.
While this is an abstract notion, theoretical mathematics has potentially far-reaching applications in communications and computer science, especially in data encryption and security.