An n-th root of a number r is a number which, if multiplied by itself n times, makes r. It is also called a radical or a radical expression. You could say that it is a number k for which this equation is true:
(for meaning of , read exponentiation.)
We write it like this: . If n is 2, then the radical expression is a square root. If it is 3, it is a cube root.
For example, because . The 8 in that example is called the radicand, the 3 is called the index, and the check-shaped part is called the radical symbol or radical sign.
Roots and powers can be changed as shown in .
The product property of a radical expression is shown in .
The quotient property of a radical expression is shown in .
This is an example of how to simplify a radical.
If two radicals are the same, they can be combined. This is when both of the indexes and radicands are the same.
- "Add and Subtract Radicals". mathbitsnotebook.com. Retrieved March 14, 2018.