The polynomial is . For a trinomial to be factorable as a perfect square, the first and last terms must be perfect squares and the middle term must be two times the square roots of the first and last terms.

1. Is the first term a perfect square?   Yes, .

2. Is the last term a perfect square?   Yes, .

3. Is the middle term equal to ?  Yes, .

Since all the three conditions are satisfy, is a perfect square trinomial.

is a perfect square trinomial.