A perfect square trinomial is a polynomial of the form (x + b)^2 = x^2 + 2bx + b^2. It is called a "perfect square" because when it is multiplied out, the resulting polynomial is a square of a binomial.
To find the perfect square trinomial of 36, we need to find two numbers that when added, give us b and when multiplied give us b^2=36.
Those two numbers are 6 and -6, since 6*-6 = -36 = 36.
So, the perfect square trinomial of 36 is (x + 6)(x - 6) = x^2 - 36
Another way to find the perfect square trinomial is to take the square root of the constant term (36) and then add and subtract that value to the variable.
√36 = 6
then x^2 + 6x - 6x + 36 = x^2 - 36
So, the perfect square trinomial of 36 is x^2 - 36.