The angle of inclination of a road is often expressed as a percent grade, which is the vertical rise divided by the horizontal run( expressed as a percent). A 9.0% grade corresponds to a road that rises 9.0 ft for every 100 ft along the horizontal. Find the angle of the inclination that corresponds to a 9.0% grade.(Round to the nearest tenth)

Respuesta :

Answer:

Explanation:

A 9.0% grade corresponds to a road that rises 9.0 ft for every 100 ft along the horizontal.

• Let the angle of inclination that corresponds to a 9.0% grade = x

The diagram below is a representation of the problem:

Using trigonometrical ratios, we find the value of angle x.

[tex]\begin{gathered} \tan\theta=\frac{Opposite}{Adjacent} \\ \implies\tan x=\frac{9}{100} \end{gathered}[/tex]

Take the arctan of both sides:

[tex]\begin{gathered} x=arctan(0.09) \\ x=5.1\degree \end{gathered}[/tex]

The angle of the inclination that corresponds to a 9.0% grade is 5.1 degrees.

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