Question

In traveling across flat land, you notice a mountain directly in front of you. Its angle of elevation (to the peak) is 3.5°. After you drive x = 11 miles closer to the mountain, the angle of elevation is 9°. Approximate the height of the mountain. (Round your answer to one decimal place.)

Answer 1

3.2 miles

Explanation:

To approximate the height of the mountain, we need to use the tangent function in trigonometry. We have two angles of elevation and the distance between the observer and the mountain, which we can use to create a right triangle.

Let h be the height of the mountain and d be the distance from the observer to the foot of the mountain.

At the first observation, we have:

tan(3.5°) = h/d

And at the second observation, when the observer is 11 miles closer to the mountain:

tan(9°) = h/(d-11)

Dividing the two equations, we have:

tan(9°) / tan(3.5°) = h/(d-11) / h/d

Solving for h, we have:

h = (d * tan(9°)) / (tan(3.5°) + 1)

We don't have an exact value for d, so we can use an estimate based on the difference in distance between the two observations.

Since d-11 = 11 miles, we have:

d = 11 * 2 = 22 miles

Using this estimate and the given angles, we can approximate the height of the mountain:

h = (22 * tan(9°)) / (tan(3.5°) + 1) = (22 * 0.156434465) / (0.066012183 + 1)

= 22 * 0.156434465 / 1.066012183 = 22 * 0.146838446 = 3.23 miles

The height of the mountain is approximately 3.2 miles to one decimal place.