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The engineers who designed an arch used the function h(x) = -0.005061x^2 + 0.499015x to describe the height of the arch (h) a distance of x from each end. Determine the distance between the ends of the arch, and the height of the arch.

User JoostD
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Answer:

1) The distance between the ends of the arch is approximately 98.6

2) The eight of the arc is approximately 12.3

Explanation:

1) The function for the height of the arch, h(x) = -0.005061·x² + 0.499015·x

Where;

x = The distance from the ends of the arch = 0, which gives;

0 = -0.005061·x² + 0.499015·x

Factorizing the above equation, we get;

0 = x·(-0.005061·x + 0.499015)

Which gives;

x = 0 or (-0.005061·x + 0.499015) = 0

-0.005061·x + 0.499015 = 0 gives;

-0.005061·x = -0.499015

x = -0.499015/(-0.005061) ≈ 98.6

Therefore, the height of the arch is zero at distance x = 0 and x = 98.6

Which gives the distance between the ends of the arch = 98.6

2) The height of the arc function h(x) = -0.005061·x² + 0.499015·x, whereby the coefficient of x² is negative, shows that it is ∩-shaped, the coordinates height and therefore, the height, is given by equating the derivative of the function to zero as follows;

d(h(x))/dt = d(-0.005061·x² + 0.499015·x)/dt = 2×(-0.005061)×x + 0.499015

d(h(x))/dt = 0 gives;

2×(-0.005061)×x + 0.499015 = 0

x = -0.499015/(2×(-0.005061)) ≈ 49.3

Therefore, the height of the arc, is the height at the point where x = 49.3

Therefore, we find the height of the arc from the height equation as follows;

h(x) = -0.005061×(49.3)² + 0.499015×49.3 ≈ 12.3

The eight of the arc is approximately 12.3.

User Rik Schoonbeek
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