Question

A tennis ball is pitched from a machine into the air; the trajectory of the ball can be expressed by the equation y=−0.05x2+45x+3
, taking into consideration that the ball is ejected from the machine 3 feet above the ground. Suppose you were to graph the parabola; at what point would the vertex be located?(1 point)
Responses

(0,3)
left parenthesis 0 comma 3 right parenthesis

(19,0)
left parenthesis 19 comma 0 right parenthesis

(8,6.2)
left parenthesis 8 comma 6.2 right parenthesis

(12,8.4)

Answers

GPT-4o mini
To find the vertex of the parabola given by the equation \( y = -0.05x^2 + 45x + 3 \), we can use the vertex formula \( x = -\frac{b}{2a} \), where \( a \) and \( b \) are the coefficients from the standard form of a quadratic equation \( y = ax^2 + bx + c \).

In this equation:
- \( a = -0.05 \)
- \( b = 45 \)

Now, calculate the x-coordinate of the vertex:

\[
x = -\frac{b}{2a} = -\frac{45}{2 \cdot -0.05} = -\frac{45}{-0.1} = 450
\]

Next, substitute \( x = 450 \) back into the equation to find the y-coordinate of the vertex:

\[
y = -0.05(450)^2 + 45(450) + 3
\]

Calculating \( 450^2 \):

\[
450^2 = 202500
\]

Now substitute back into the equation:

\[
y = -0.05(202500) + 45(450) + 3
\]
\[
y = -10125 + 20250 + 3
\]
\[
y = 10125 + 3 = 10128
\]

Thus, the vertex of the parabola is located at \( (450, 10128) \).

In your multiple-choice options, since this calculation does not match any of the given choices, it seems I may have made an error in the measurement context. Could you verify the total calculations or provide any constraints? However, based on standard parabola calculation, the above procedure is accurate.