Which of the following graphs is a possible sketch of the polynomial f(x)=2x3(x−2)2 ?(1 point)

1 answer

To analyze the polynomial \( f(x) = 2x^3(x - 2)^2 \), we can derive its key features, including its roots, multiplicities, end behavior, and any potential turning points.

  1. Roots and Multiplicities:

    • The polynomial can be factored as \( 2x^3(x - 2)^2 \).
    • This gives us roots at \( x = 0 \) with multiplicity 3 (odd), and \( x = 2 \) with multiplicity 2 (even).
  2. End Behavior:

    • The leading term is \( 2x^5 \) (since \( 2x^3 \) has 3 and \( (x-2)^2 \) has 2, their degrees add up to 5).
    • Since the leading coefficient (2) is positive and the degree of the polynomial is odd, as \( x \to -\infty \), \( f(x) \to -\infty \), and as \( x \to +\infty \), \( f(x) \to +\infty \).
  3. Behavior at Roots:

    • At \( x = 0 \): Since the root has an odd multiplicity (3), the graph will cross the x-axis at this point.
    • At \( x = 2 \): Since the root has an even multiplicity (2), the graph will touch (but not cross) the x-axis at this point.
  4. Summary of Graph Features:

    • The graph will start from the bottom left (as \( x \to -\infty \)), cross the x-axis at the origin (0,0), and then rise towards the point (2,0) where it will lower and return to the x-axis but will not cross it (due to the even multiplicity).
    • Finally, it will continue to rise towards the top right as \( x \to +\infty \).

With this analysis, a valid sketch of the graph of \( f(x) = 2x^3(x - 2)^2 \) should show:

  • An x-intercept at \( x = 0 \) where the graph crosses the axis.
  • A touch at \( x = 2 \) where the graph remains on the x-axis without crossing.
  • Overall increasing behavior from left to right.

You would need to select a graph from the options provided that demonstrates these characteristics: an x-axis crossing at 0, touching at 2, and the correct end behavior.