Answer
perfect square trinomial
Work Step by Step
When a binomial is multiplied by itself again, the resulting trinomial is called a perfect square trinomial.
For example, $(x + 1)(x + 1) = x^2 + x + x + 1 = x^2 + 2x + 1$ and $x^2 + 2x + 1$ is a perfect square trinomial of the binomial $(x + 1)$.