The root is the inverse operation to the exponentiation. Given two numbers, called the radicand and index, find a third number, which is called the root, such that when elevated to the index, it is equal to the radicand.
The index for the square root is 2, although in this case it is omitted.
The square root of a number, a, is accurate when a number is found, b, which when elevated to the square is equal to the radicand: b2 = a.
Exact square root
An exact square root has the remainder 0.
Radicand = (Exact root)2
These are the numbers that have exact square roots.
1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, ...
Not exact square root
If a number is not a perfect square, the square root is no exact.
Radicand = (Root)2 + Remainder