Examples
16 is a perfect square because 4² = 16 and 4 is a whole number.
20 is not a perfect square because [latex]\sqrt {20}[/latex] is not a whole number.
Educational Note
The expression “perfect square” should not be applied to any
algebraic expression.
So, the
trinomial x² – 4
x + 4 which is equal to (
x – 2)² can only be called a perfect square if
x – 2 is a whole number. Instead, we should say that the trinomial
x² – 4
x + 4 is the square of the
binomial (
x – 2).
