SOLUTION: A ball is thrown vertically upward. After t seconds, its height h (in feet) is given by the function h(t)=40t-16t^2. After how long will it reach its maximum height?

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Question 1089154: A ball is thrown vertically upward. After t seconds, its height h (in feet) is given by the function h(t)=40t-16t^2. After how long will it reach its maximum height?
Answer by ikleyn(52802) About Me  (Show Source):
You can put this solution on YOUR website!
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The quadratic function h(t) = -16t%5E2+%2B+40t has the maximum at t = -40%2F%28-2%2A16%29 = 40%2F32 = 5%2F4 of a second.

On finding the maximum/minimum of a quadratic function see the lessons
    - HOW TO complete the square to find the minimum/maximum of a quadratic function
    - Briefly on finding the minimum/maximum of a quadratic function
    - HOW TO complete the square to find the vertex of a parabola
    - Briefly on finding the vertex of a parabola


Also, you have this free of charge online textbook in ALGEBRA-I in this site
    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.

The referred lessons are the part of this textbook under the topic "Finding minimum/maximum of quadratic functions".


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For a projectile thrown/shot/launched vertically up see the lessons
    - Problem on a projectile moving vertically up and down
    - Problem on an arrow shot vertically upward
    - Problem on a ball thrown vertically up from the top of a tower
    - Problem on a toy rocket launched vertically up from a tall platform

The referred lessons are the part of the above mentioned textbook under the topic "Projectiles launched/thrown and moving vertically up and dawn".