Question
b) \( f(x)=x^{2}+6 x+9 \)
Ask by Mills Robbins. in South Africa
Jan 24,2025
Real Tutor Solution
Tutor-Verified Answer
Answer
\( f(x) = (x + 3)^2 \)
Solution
It looks like you're working with the quadratic function:
\[ f(x) = x^{2} + 6x + 9 \]
Let's analyze and simplify this function.
### 1. **Factoring the Quadratic**
To factor the quadratic expression, we look for two numbers that multiply to **9** (the constant term) and add up to **6** (the coefficient of the middle term).
- The numbers **3** and **3** satisfy this because:
\[
3 \times 3 = 9 \quad \text{and} \quad 3 + 3 = 6
\]
So, the factored form of the quadratic is:
\[
f(x) = (x + 3)(x + 3) = (x + 3)^2
\]
### 2. **Vertex Form**
The factored form \((x + 3)^2\) indicates that the vertex of the parabola represented by \(f(x)\) is at **\((-3, 0)\)**.
### 3. **Roots of the Function**
Setting \(f(x) = 0\) to find the roots:
\[
(x + 3)^2 = 0 \implies x = -3
\]
This means the function has a **double root** at \(x = -3\).
### 4. **Graphical Interpretation**
The graph of \(f(x)\) is a parabola that opens ** upwards** (since the coefficient of \(x^2\) is positive) and touches the x-axis at the point \((-3, 0)\).
### 5. **Derivative (Optional)**
If you're interested in calculus aspects, the derivative of \(f(x)\) with respect to \(x\) is:
\[
f'(x) = 2x + 6
\]
Setting the derivative to zero to find critical points:
\[
2x + 6 = 0 \implies x = -3
\]
This confirms that the vertex at \(x = -3\) is indeed the minimum point of the function.
---
**Summary:**
- **Factored Form:** \(f(x) = (x + 3)^2\)
- **Vertex:** \((-3, 0)\)
- **Roots:** \(x = -3\) (double root)
If you have a specific aspect you'd like to delve into further, feel free to ask!
Reviewed and approved by the UpStudy tutoring team
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The Deep Dive
Did you know that the function \( f(x) = x^2 + 6x + 9 \) is actually a perfect square trinomial? It can be rewritten as \( f(x) = (x + 3)^2 \)! This means its graph is a parabola that opens upwards with its vertex at the point (-3, 0). It also has a minimum value of 0 at this vertex. When working with quadratic functions like this, remember that completing the square can help you easily identify important features such as the vertex and intercepts. A common mistake is forgetting to correctly factor out or distribute terms when doing so. Just be patient, and take it step by step!