Question

PLEASE HELP ME QUICK

Lori tosses a ball into the air. The equation y = –16(x – 1)2 + 25 models the height, y, in feet, of the ball after x seconds. What is the maximum height the ball reaches?


1 ft

9 ft

16 ft

25 ft

Answer 1

16 I’m pretty sure I don’t exactly know

Answer 2

Answer: D. 25 ft

Explanation:

When graphing a parabola in the format
`y = a(x-h)^2+k`, know that:

• if a is positive, the parabola points upwards (meaning that there is only a minimum value, no maximum exists)

• if a is negative, the parabola points downwards (there is a maximum, but no minimum)

You can try playing around with these values on a graphing calculator like Desmos!

In both cases, k would be the minimum or maximum value.

For this problem, k = 25. So, the maximum is 25 ft.

Additional information:

• the parabola equation is in vertex form, so (h, k) is the vertex