When you multiply a number by itself, you raise it to a power. A power is a product in which all of the factors are the same. To indicate that you are raising a number to a given power, you employ an exponent. An exponent tells you the number of times by which you multiply a number by itself to arrive at the value you seek. Consider the following expressions:
|a × a = a2||2 × 2 = 22 = 4|
|a × a × a = a3||2 × 2 × 2 = 23 = 8|
|a × a × a × a = a4||2 × 2 × 2 × 2 = 24 = 16|
In the expression a2, the a is the base of the expression, and the 2 is the exponent. The base provides the number you use in the multiplication. The exponent tells you how many times to multiply the number by itself.
When you use a negative number as ...