Hello, andi01!

Think of what you said . . .The path of a golf ball can be modeled by a quadratic equation.

The path of a ball hit an angle of 10° can be modeled by:

where is the height in meters and is the horizontal distance.

a) What is the maximum height reached by the ball?

The answer is 20m.

Usually I would just sub in 0 for d to find h. . . Why?

You let .

The ball has not moved yet.

What is its height?

. . Obviously it'sstill on the ground!

Here's one way of looking at it:

The graph of is a down-opening parabola:

Its maximum is at its vertex.

The vertex is at: .

The maximum height is: . m.