The function f(x) = -16x^2 + 64x models the height of a golf ball f, in feet, x sec...
Check the final answer first, then review the worked steps.
Problem
The function f(x) = -16x^2 + 64x models the height of a golf ball f, in feet, x seconds after it is hit. What is the vertex of the function? What does the vertex indicate about the ball?
Step-by-step solution
For the function $f(x) = -16x^2 + 64x$, the x-coordinate of the vertex is $-b/(2a) = -64/(2*(-16)) = 2$. The y-coordinate is $f(2) = -16(2)^2 + 64(2) = -64 + 128 = 64$. The vertex is $(2, 64)$. This indicates the maximum height of the golf ball.
Answer
2, 64