Wilma is asked to sketch a graph of m(x)=(7x-1)^7(x+3)^2(5x+2)


. How many turning points should her sketch include?

A
at most 5

B
at most 9

C
at most 7

D
at most 10

1 answer

To determine how many turning points the function \( m(x) = (7x-1)^7(x+3)^2(5x+2) \) can have, we first need to analyze the degree of the polynomial.

  1. Identify the degrees of each factor:

    • \( (7x - 1)^7 \) has a degree of 7.
    • \( (x + 3)^2 \) has a degree of 2.
    • \( (5x + 2) \) has a degree of 1.
  2. Add the degrees together to find the overall degree of \( m(x) \): \[ \text{Degree of } m(x) = 7 + 2 + 1 = 10. \]

  3. Turning points: A polynomial of degree \( n \) can have at most \( n - 1 \) turning points.

For \( m(x) \) which is of degree 10: \[ \text{Maximum number of turning points} = 10 - 1 = 9. \]

Thus, for her sketch, Wilma should include at most 9 turning points.

The correct answer is B: at most 9.