Question

The gas mileage m (x) (in mpg) for a certain vehicle can be approximated by m (x) = -0.03x^2+2.673x- 35.012, where x is the speed of the vehicle in mph.
(a) Determine the speed at which the car gets its maximum mileage. Round your answer to the nearest mph.?

Answers

GPT-4o mini
To find the speed at which the car gets its maximum mileage, we need to determine the vertex of the quadratic function represented by \( m(x) = -0.03x^2 + 2.673x - 35.012 \). The quadratic function can be expressed in the form \( ax^2 + bx + c \), where:

- \( a = -0.03 \)
- \( b = 2.673 \)
- \( c = -35.012 \)

The x-coordinate of the vertex for a quadratic equation \( y = ax^2 + bx + c \) can be calculated using the formula:

\[
x = -\frac{b}{2a}
\]

Substituting in our values for \( a \) and \( b \):

\[
x = -\frac{2.673}{2 \times -0.03} = -\frac{2.673}{-0.06} = \frac{2.673}{0.06}
\]

Calculating the right-hand side:

\[
\frac{2.673}{0.06} = 44.55
\]

Rounding to the nearest mph, the speed at which the car gets its maximum mileage is:

\[
\boxed{45} \text{ mph}
\]