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    Radicals


    For positive integer n and real number a, any real number x such that xn = a is called an nth root of a.  
    • For n = 2, an nth root is called a square root
    • For n = 3, an nth root is called a cube root
    • The principal nth root of a, which is the positive nth root of a is denoted by
    • The principal nth root of 0 equals zero:
    • If a < 0, the principal nth root of a, is defined as a real number only when n is odd
    Terminology:

     The symbol is referred to as the radical sign (or radical) while the positive integer n is called the index and real number a under the radical is the radicand.
    Considering:



    It follows that:
    index = 3,  
    radicand  = 125,  
    principal 3rd root of radicand = 5


    Properties of Radicals: