B.  Key Lesson Marker


In general, for positive values of a,

This means that when the exponent of the radicand and the index are equal, the radical is equal to the base of the radicand.

Example 2

Represent in two different ways.


5 × 5 × 5 = 125 or 53 = 125


There is a slight, but important, distinction to be made between the following two statements:

1. Solve the equation x2 = 36.

2. Evaluate .

  1. Solve the equation x2 = 36.

    Why?
    Substituting each of the solutions into the original equation will give 36.

  1. Evaluate .



    Why?
    By convention, the symbol itself represents the principal (positive) square root. The     principal square root of 36 is +6. The negative square root is represented as follows:



Principal Square Root
the positive value of the square root of a number