Use the zeros to determine which of the following graphs is a sketch of the polynomial  f(x)=−x(x+2)2 .(1 point)ResponsesImage with alt text: A curve with arrows at both the ends is plotted on a coordinate plane. The x-axis ranges from negative 6 to 2 in unit increments. The y-axis does not show any values.Image with alt text: A downward-opening parabola is plotted on a coordinate plane with the x-axis ranging from negative 4 to 2 in unit increments.   Image with alt text: A curve passes through quadrants 2 and 4 on a coordinate plane with the x-axis ranging from negative 6 to 2 in unit increments.Image with alt text: A curve passes through quadrants 2 and 4 on a coordinate plane with the x-axis ranging from negative 2 to 6 in unit increments.Skip to navigationpage 14 of 14

1 answer

To determine which graph represents the polynomial \( f(x) = -x(x+2)^2 \), we first need to analyze the function.

  1. Identify the Zeros: The zeros of the polynomial are found by setting \( f(x) = 0 \): \[ -x(x+2)^2 = 0 \] This gives us: \[ x = 0 \quad \text{and} \quad (x+2)^2 = 0 \implies x = -2 \] Thus, the zeros of the function are \( x = 0 \) and \( x = -2 \). The zero at \( x = -2 \) has multiplicity 2 because of the squared term.

  2. Behavior at the Zeros:

    • At \( x = 0 \), the graph crosses the x-axis because this zero has odd multiplicity (1).
    • At \( x = -2 \), the graph touches the x-axis but does not cross it because this zero has even multiplicity (2).
  3. End Behavior: Since the leading coefficient of the polynomial is negative (as indicated by the minus sign in front), the ends of the graph will both point downwards:

    • As \( x \to -\infty \), \( f(x) \to +\infty \)
    • As \( x \to +\infty \), \( f(x) \to -\infty \)
  4. Sketching the Graph:

    • The graph will start high on the left side (as \( x \to -\infty \)) and will approach the x-axis at \( x = -2 \), touching it there.
    • Then, it will go up to cross the x-axis at \( x = 0 \) before heading downwards as \( x \) increases beyond 0.

Now, based on this analysis, the correct graph should:

  • Touch at \( x = -2 \)
  • Cross at \( x = 0 \)
  • Start high on the left and end low on the right.

Among the options given, select the graph that matches these characteristics to conclude.