The hight, the feet, of a javelin t seconds afther it is moldeled by the function (t) = 4t^2 + 24t + 6. Afther how many seconds does the javelin reah its maximum height of 42 feet?

The max height will be reached after 3 seconds.

You have a typo in your equation. For this type of quadratic equation, it always starts out with a negative coefficient of the t squared term.

To find the x-coordinate of the vertex, we just need to use the expression: - b/2a.

Then, we have:

-24 / (2 (-4))

-24 / - 8

3