Perfect Square Trinomial Calculator

Use our perfect square trinomial calculator to calculate perfect square trinomial forms and factor them fast. Learn what is a perfect square trinomial, what makes a trinomial a perfect square, how to find perfect square trinomial patterns, the perfect square trinomial formula, and see perfect square trinomial formula examples.

a
Coefficient of x² (a ≠ 0). Whole number.
b
Coefficient of x. Whole number.
c
Constant term. Whole number.
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What is a Perfect Square Trinomial?

A perfect square trinomial is a trinomial that can be written as the square of a binomial. In other words, it factors into something like (a + b)² or (a − b)².

If you’re asking what makes a trinomial a perfect square, it follows a very specific pattern: the first and last terms are perfect squares, and the middle term is twice the product of their square roots (with a matching sign).

A perfect square trinomial calculator helps you recognize the pattern and factor quickly, which is why it’s often used as a factor perfect square trinomial calculator in algebra.

Perfect Square Trinomial Formula

Perfect square trinomials come from expanding (a ± b)². These identities are the core formula for perfect square trinomial problems.

Perfect square trinomial (plus) =
a^2 + 2ab + b^2 = (a + b)^2

Middle term is +2ab.

Perfect square trinomial (minus) =
a^2 - 2ab + b^2 = (a - b)^2

Middle term is -2ab.

a
= Square root (or factor) of the first term
b
= Square root (or factor) of the last term
2ab
= The middle term (twice the product)
Perfect square trinomial formula examples
x^2 + 10x + 25 = (x + 5)^2

Because 25 = 5^2 and 10x = 2·x·5.

Another example
4x^2 - 12x + 9 = (2x - 3)^2

Because 4x^2 = (2x)^2, 9 = 3^2, and -12x = -2·(2x)·3.

How to Use the Perfect Square Trinomial Calculator

  1. 1

    Enter the trinomial expression (for example, x^2 + 10x + 25).

  2. 2

    The calculator checks if the first and last terms are perfect squares.

  3. 3

    It verifies whether the middle term matches ±2ab.

  4. 4

    If it matches, it returns the factored form (a ± b)^2.

Frequently Asked Questions

What is a perfect square trinomial in math?

It’s a trinomial that factors into a binomial squared, like (a + b)^2 or (a − b)^2.

What is a perfect square trinomial example?

x^2 + 6x + 9 is a perfect square trinomial because it factors as (x + 3)^2.

How to find perfect square trinomial?

Check whether the first and last terms are perfect squares, then see if the middle term equals ±2 times the product of their square roots.

What makes a trinomial a perfect square?

It must match the pattern a^2 ± 2ab + b^2. The middle term must be exactly twice the product of a and b (with the correct sign).

How to solve perfect square trinomial / factor it?

Take square roots of the first and last terms to get a and b, then write (a ± b)^2, using the sign from the middle term.

Can a perfect square trinomial be negative?

A perfect square trinomial equals (a ± b)^2, which is always ≥ 0 for real numbers. Individual terms or the middle term can be negative (like a^2 − 2ab + b^2), but the expression as a whole is not negative for real inputs.

Which trinomials are perfect square trinomials?

Those that match a^2 ± 2ab + b^2. If the middle term doesn’t match ±2ab exactly, it’s not a perfect square trinomial.

Is this a factor perfect square trinomial calculator?

Yes. It identifies the pattern and returns the factored binomial-squared form when the trinomial is a perfect square.