Questions: Consider the following polynomial functions.
f(x)=(x+1)^2(x-3)
h(x)=x^4-3x^3
Choose the graph of each function from the choices below.
Transcript text: Consider the following polynomial functions.
$f(x)=(x+1)^{2}(x-3)$
$h(x)=x^{4}-3 x^{3}$
Choose the graph of each function from the choices below.
Solution
Solution Steps
Step 1: Analyze f(x)
f(x) = (x+1)²(x-3) has zeros at x = -1 (multiplicity 2, so it touches the x-axis) and x = 3 (multiplicity 1, so it crosses the x-axis). The leading term is x³ indicating the graph rises to the right and falls to the left.
Step 2: Identify the graph of f(x)
Graph A matches the analysis: touches x-axis at x=-1, crosses at x=3, and has the correct end behavior.
Step 3: Analyze h(x)
h(x) = x⁴ - 3x³ = x³(x-3) has zeros at x = 0 (multiplicity 3, so it crosses the x-axis and has an inflection point) and x = 3 (multiplicity 1, so it crosses the x-axis). The leading term is x⁴, meaning both ends go in the same direction, upwards.
Step 4: Identify the graph of h(x)
Graph D matches the analysis: crosses at x=0 and x=3, has an inflection point at x=0 and has the correct end behavior.