The height (h metres) of a golf ball is given by h = −x2 + 100x, where x metres is the
horizontal distance from where the ball was hit.

a Find the values of x when h = 0.
b Interpret your answer from part a.
c Find how far the ball has travelled horizontally when the height is 196 m.



Answer :

Answer:

Step-by-step explanation:

Part a: Find the values of

x when

=

0

h=0.

The height

h of the golf ball is given by the equation:

=

2

+

100

h=−x

2

+100x

To find the values of

x when

=

0

h=0, we set

=

0

h=0 in the equation:

0

=

2

+

100

0=−x

2

+100x

Factor out

x:

(

+

100

)

=

0

x(−x+100)=0

This equation will be true if either

=

0

x=0 or

+

100

=

0

−x+100=0.

=

0

x=0

+

100

=

0

−x+100=0

=

100

−x=−100

=

100

x=100

So, the values of

x when

=

0

h=0 are

=

0

x=0 and

=

100

x=100.

Part b: Interpret your answer from part a.

From part a, we found that

=

0

x=0 and

=

100

x=100 are the values of

x when

=

0

h=0.

=

0

x=0 represents the horizontal distance from where the ball was hit when the height

h is 0. This means the ball is on the ground at the point where it was initially hit.

=

100

x=100 represents the horizontal distance from where the ball was hit when the height

h is 0 again. This indicates that the ball has traveled 100 meters horizontally and has returned to the ground level.

Part c: Find how far the ball has traveled horizontally when the height is 196 m.

We are given that

=

196

h=196 m. We need to find

x, the horizontal distance traveled, when

=

196

h=196.

Use the equation for

h:

2

+

100

=

196

−x

2

+100x=196

Subtract 196 from both sides to set the equation to 0:

2

+

100

196

=

0

−x

2

+100x−196=0

Now, solve this quadratic equation using the quadratic formula

=

±

2

4

2

x=

2a

−b±

b

2

−4ac

, where

=

1

a=−1,

=

100

b=100, and

=

196

c=−196.

Calculate the discriminant:

Δ

=

2

4

=

10

0

2

4

(

1

)

(

196

)

Δ=b

2

−4ac=100

2

−4(−1)(−196)

Δ

=

10000

784

Δ=10000−784

Δ

=

9216

Δ=9216

Now, find

x:

=

100

±

9216

2

(

1

)

x=

2(−1)

−100±

9216

=

100

±

96

2

x=

−2

−100±96

Calculate the two possible values of

x:

1

=

100

+

96

2

=

4

2

=

2

x

1

=

−2

−100+96

=

−2

−4

=2

2

=

100

96

2

=

196

2

=

98

x

2

=

−2

−100−96

=

−2

−196

=98

Therefore, the ball has traveled horizontally

=

2

x=2 meters and

=

98

x=98 meters when the height is 196 m.

So, the ball has traveled 2 meters and 98 meters horizontally when the height is 196 m.