Let’s clarify the concept of a perfect square trinomial.

What is a Perfect Square Trinomial?

A perfect square trinomial is a quadratic expression that can be factored into a binomial squared. The general form of a perfect square trinomial is:

$a^2 + 2ab + b^2 = (a + b)^2$

or

$a^2 - 2ab + b^2 = (a - b)^2$

Breaking Down the Formula:

1. $a^2$: This is the square of the first term of the binomial.
2. $2ab$: This is twice the product of the first and second terms of the binomial.
3. $b^2$: This is the square of the second term of the binomial.

Example to Understand:

Consider the quadratic expression $x^2 + 6x + 9$.

1. Identify $a^2$: Here, $a^2 = x^2$, so $a = x$.
2. Identify $b^2$: Here, $b^2 = 9$, so $b = 3$.
3. Check the middle term $2ab$:
   • $2ab = 2 \times x \times 3 = 6x$, which matches the middle term in the original expression.

Since it matches, the expression $x^2 + 6x + 9$ can be factored as: $x^2 + 6x + 9 = (x + 3)^2$

Applying to Your Problem:

For your equation $9q^2 + 12q + 4 = 0$:

1. Identify $a^2$: Here, $a^2 = 9q^2$, so $a = 3q$.
2. Identify $b^2$: Here, $b^2 = 4$, so $b = 2$.
3. Check the middle term $2ab$:
   • $2ab = 2 \times 3q \times 2 = 12q$, which matches the middle term.

Thus, $9q^2 + 12q + 4$ can be factored as: $9q^2 + 12q + 4 = (3q + 2)^2$

This means the equation is a perfect square trinomial.

Would you like to explore more about perfect square trinomials, or do you have any further questions?

Related Questions:

1. How do you recognize a perfect square trinomial among other quadratics?
2. What is the difference between a perfect square trinomial and a regular quadratic equation?
3. Can the method of completing the square always be used to form a perfect square trinomial?
4. What role does the discriminant play in identifying perfect square trinomials?
5. How would you apply the concept of perfect square trinomials in solving word problems?

Tip:

To quickly determine if a quadratic expression is a perfect square trinomial, check if the middle term equals twice the product of the square roots of the first and last terms.