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Question

1. The height, h, in metres, of a golf ball t seconds after it is hit can be modelled by the function
   h(t) = -4.9t² + 32t + 0.2. When is the height of the ball 15m? solve graphically and algebraically include sketch and explain. 

Answer 1

Step 1:

The modelled function of height

Height of the ball is .

Substitute in the height function.

Multiply each side by .

Step 2:

Compare the equation with standard quadratic form .

Roots of the quadratic equation are  .

Substitute corresponding    values in above formula.

and .

Step 3:

Graph:

Observe the graph:

At sec and sec height of the ball is m.

Solution:

Height of the ball is m at sec and sec.