Questions: Use the graph to write the formula for a polynomial function of least degree.
f(x)=
Transcript text: Use the graph to write the formula for a polynomial function of least degree.
\[
f(x)=
\]
$\square$
Solution
Solution Steps
Step 1: Identify the roots of the polynomial
The graph crosses the x-axis at $x = -2$, $x = 3$, and appears to touch the x-axis at $x=0$. Therefore, the roots are $x=-2$, $x=0$, and $x=3$.
Step 2: Determine the multiplicity of each root
Since the graph crosses the x-axis at $x=-2$ and $x=3$, these roots have an odd multiplicity. The least odd multiplicity is 1. Since the graph only touches the x-axis at $x=0$, this root has an even multiplicity. The least even multiplicity is 2.
Step 3: Construct the polynomial
The polynomial can be written in the form $f(x) = a(x - r_1)^{m_1}(x - r_2)^{m_2}(x - r_3)^{m_3}$, where $r_i$ are the roots and $m_i$ are their multiplicities. Thus, the polynomial is $f(x) = a(x - (-2))(x - 0)^2(x - 3) = ax^2(x+2)(x-3)$.
Step 4: Determine the leading coefficient
The graph passes through the point $(1, -2)$. Substituting $x=1$ and $f(x)=-2$ into the equation, we have:
$-2 = a(1)^2(1+2)(1-3)$
$-2 = a(1)(3)(-2)$
$-2 = -6a$
$a = \frac{1}{3}$