We want to find the zeros of this polynomial:

[tex]\[ p(x)=\left(x^2 + 4x + 3\right)\left(x^2 - 4\right) \][/tex]

Plot all the zeros (x-intercepts) of the polynomial on the interactive graph.



Answer :

To find the zeros of the polynomial [tex]\( p(x) = (x^2 + 4x + 3)(x^2 - 4) \)[/tex], we need to determine the values of [tex]\( x \)[/tex] for which [tex]\( p(x) = 0 \)[/tex]. This can be done by setting each factor of the polynomial to zero and solving for [tex]\( x \)[/tex].

The polynomial is given by:
[tex]\[ p(x) = (x^2 + 4x + 3)(x^2 - 4) \][/tex]

### Step-by-Step Solution:

#### Step 1: Solve [tex]\( x^2 + 4x + 3 = 0 \)[/tex]

This is a quadratic equation. To solve it, we can use the quadratic formula:
[tex]\[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \][/tex]
For the quadratic [tex]\( x^2 + 4x + 3 \)[/tex], the coefficients are [tex]\( a = 1 \)[/tex], [tex]\( b = 4 \)[/tex], and [tex]\( c = 3 \)[/tex]. Plugging these into the quadratic formula:

[tex]\[ x = \frac{-4 \pm \sqrt{4^2 - 4 \cdot 1 \cdot 3}}{2 \cdot 1} = \frac{-4 \pm \sqrt{16 - 12}}{2} = \frac{-4 \pm \sqrt{4}}{2} = \frac{-4 \pm 2}{2} \][/tex]

This yields two solutions:
[tex]\[ x = \frac{-4 + 2}{2} = \frac{-2}{2} = -1 \quad \text{and} \quad x = \frac{-4 - 2}{2} = \frac{-6}{2} = -3 \][/tex]

So, [tex]\( x = -1 \)[/tex] and [tex]\( x = -3 \)[/tex] are zeros of the factor [tex]\( x^2 + 4x + 3 \)[/tex].

#### Step 2: Solve [tex]\( x^2 - 4 = 0 \)[/tex]

This is another quadratic equation that can be factored directly as:

[tex]\[ x^2 - 4 = (x - 2)(x + 2) \][/tex]

Setting each factor to zero, we get:
[tex]\[ x - 2 = 0 \quad \Rightarrow \quad x = 2 \][/tex]
[tex]\[ x + 2 = 0 \quad \Rightarrow \quad x = -2 \][/tex]

So, [tex]\( x = 2 \)[/tex] and [tex]\( x = -2 \)[/tex] are zeros of the factor [tex]\( x^2 - 4 \)[/tex].

### Conclusion:

The zeros of the polynomial [tex]\( p(x) = (x^2 + 4x + 3)(x^2 - 4) \)[/tex] are [tex]\( x = -3 \)[/tex], [tex]\( x = -2 \)[/tex], [tex]\( x = -1 \)[/tex], and [tex]\( x = 2 \)[/tex].

### Plotting the Zeros:

Let's plot the zeros on the [tex]\( x \)[/tex]-axis. The zeros are the points where the polynomial intersects the [tex]\( x \)[/tex]-axis.

```
Zero | Coordinate
-------------------
-3 | (-3, 0)
-2 | (-2, 0)
-1 | (-1, 0)
2 | (2, 0)
```

[tex]\[ \begin{tikzpicture} \begin{axis}[ axis lines = middle, xlabel = $x$, ylabel = $y$, ymin = -1.5, ymax = 1.5, xmin = -4, xmax = 3, ytick={\empty}, xtick={-3,-2,-1,2} ] % Plot the points \addplot[mark=*] coordinates {(-3,0)(-2,0)(-1,0)(2,0)}; \end{axis} \end{tikzpicture} \][/tex]

In a graph, the zeros of the polynomial [tex]\( p(x) \)[/tex] are highlighted as points [tex]\((-3,0)\)[/tex], [tex]\((-2,0)\)[/tex], [tex]\((-1,0)\)[/tex], and [tex]\((2,0)\)[/tex].

This interactive plot shows the locations of the zeros on the [tex]\( x \)[/tex]-axis.