Questions: Identify which of the graphs could be the graph of a polynomial function.
f(x)=-x^2(x-2)(x+1)
Transcript text: Identify which of the graphs could be the graph of a polynomial function.
\[
f(x)=-x^{2}(x-2)(x+1)
\]
A)
B)
C)
D)
Solution
Solution Steps
Step 1: Identify the polynomial function
The given polynomial function is \( f(x) = -x^2(x - 2)(x + 1) \).
Step 2: Determine the degree of the polynomial
The polynomial \( f(x) = -x^2(x - 2)(x + 1) \) can be expanded to find its degree:
\[ f(x) = -x^2(x^2 - x - 2) = -x^4 + x^3 + 2x^2 \]
The degree of the polynomial is 4.
Step 3: Analyze the end behavior of the polynomial
Since the leading term is \(-x^4\), the end behavior of the polynomial is:
As \( x \to \infty \), \( f(x) \to -\infty \)
As \( x \to -\infty \), \( f(x) \to -\infty \)
Step 4: Identify the roots of the polynomial
The roots of the polynomial are found by setting \( f(x) = 0 \):
\[ -x^2(x - 2)(x + 1) = 0 \]
The roots are \( x = 0 \) (with multiplicity 2), \( x = 2 \), and \( x = -1 \).
Step 5: Match the graph with the polynomial characteristics
The graph should have roots at \( x = 0 \), \( x = 2 \), and \( x = -1 \).
The graph should have end behavior where both ends go to \(-\infty\).
Final Answer
The graph that matches the polynomial \( f(x) = -x^2(x - 2)(x + 1) \) is Graph A.