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AVprozaik [17]
3 years ago
14

A bridge on a river is modeled by the equation h = -0.2d2 + 2.25d, where h is the height and d is the horizontal distance. For c

leaning and maintenance purposes a worker wants to tie a taut rope on two ends of the bridge so that he can slide on the rope. The rope is at an angle defined by the equation -d + 6h = 21.77. If the rope is attached to the bridge at points A and B, such that point B is at a higher level than point A, at what distance from the ground level is point A?
Mathematics
2 answers:
icang [17]3 years ago
6 0
The answer is 2.2108
Solution:
first equation:
h = -0.2d² + 2.25d-d + 6h = 21.77
2nd equation:-d + 6h = 21.77d = 6h - 21.77
Then substitute:h = -0.2(6h - 21.77)² + 2.25(6h - 21.77)h = 3.9968
Answer:d = 2.2108

algol133 years ago
6 0

Answer:

Point A is approximately 4 unit above the ground.

Step-by-step explanation:

A bridge on a river is modeled by the equation h = -0.2d² + 2.25d -------(1)

Where h is the height and d is the horizontal distance.

For cleaning and maintenance purpose a worker wants to tie a taut a rope on two ends of the bridge so that he can slide on the rope.

The rope is at an angle defined by the equation

-d + 6h = 21.77

d - 6h = -21.77

d = 6h - 21.77 -------(2)

Now we have to find the value of h which is the distance from the ground level.

Now we substitute d from equation 2 to equation 1

h = -0.2(6h - 21.77)²+ 2.25(6h - 21.77)

h = -0.2(36h²+ 473.9329 - 261.24h) + 13.5h - 48.9825

h = -(7.2h² + 94.79 - 52.25h) + 13.5h - 48.98

h = -7.2h² - 94.79 + 52.25h + 13.5h - 48.98

h = -7.2h² + 65.75h - 143.77

0 = -7.2h² + 65.75h - h - 143.77

0 = -7.2h² + 64.75h - 143.77

7.2h²- 64.75h + 143.77 = 0

Now we divide the equation by 7.2

h² - 9h + 20 = 0

h² - 5h - 4h + 20 = 0

h(h - 5) - 4(h - 5) = 0

(h - 4)(h - 5) = 0

h = 4 or 5

Therefore, point A is approximately 4 unit above the ground.

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Step-by-step explanation:

We are given following information about eye colors of 204 Scandinavian men and their female partners.

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Blue        78         23            13          114

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P(female=blue | male=brown) = 19/54

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P(female=blue | male=green) = 11/36

P(female=blue | male=green) = 0.31

e) Does it appear that the eye colors of male respondents and their partners are independent? Explain

If the following relation holds true then we can conclude that the eye colors of male respondents and their partners are independent.

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