3. Surveyor 1 measures the angle of elevation of the peak of a mountain to be 35
degrees. Surveyor 2 who is 1200
feet closer on a straight path measures the
angle of
elevation to be 42 degrees. How
tall is the mountain?



Answer :

Sure, let's work through this problem step-by-step.

### Given:
- Angle measured by Surveyor 1 ([tex]\(\angle_1\)[/tex]): 35 degrees
- Angle measured by Surveyor 2 ([tex]\(\angle_2\)[/tex]): 42 degrees
- Distance between Surveyor 1 and Surveyor 2 ([tex]\(d\)[/tex]): 1200 feet

We want to determine the height of the mountain ([tex]\(h\)[/tex]).

### Steps to solve:

1. Convert angles to radians:
- [tex]\(\angle_1 = 35\)[/tex] degrees [tex]\(= 0.6108652381980153\)[/tex] radians
- [tex]\(\angle_2 = 42\)[/tex] degrees [tex]\(= 0.7330382858376184\)[/tex] radians

2. Calculate the tangents of the angles:
- [tex]\(\tan(\angle_1) = 0.7002075382097097\)[/tex]
- [tex]\(\tan(\angle_2) = 0.9004040442978399\)[/tex]

3. Establish the geometric relationship:
The problem can be visualized as two right triangles sharing a vertical side (the height of the mountain) with their bases along the same horizontal line.

From Surveyor 1:
[tex]\[ \tan(\angle_1) = \frac{h}{b + d} \][/tex]
From Surveyor 2:
[tex]\[ \tan(\angle_2) = \frac{h}{b} \][/tex]
Here, [tex]\(b\)[/tex] is the base distance from Surveyor 2 to the projection of the height on the ground.

4. Solve for the base [tex]\(b\)[/tex]:
From Surveyor 2's perspective:
[tex]\[ h = b \cdot \tan(\angle_2) \][/tex]
From Surveyor 1’s perspective:
[tex]\[ h = (b + d) \cdot \tan(\angle_1) \][/tex]
Equating the two expressions for [tex]\(h\)[/tex]:
[tex]\[ b \cdot \tan(\angle_2) = (b + d) \cdot \tan(\angle_1) \][/tex]
[tex]\[ b \cdot \tan(\angle_2) = b \cdot \tan(\angle_1) + d \cdot \tan(\angle_1) \][/tex]
Rearrange to solve for [tex]\(b\)[/tex]:
[tex]\[ b \cdot (\tan(\angle_2) - \tan(\angle_1)) = d \cdot \tan(\angle_1) \][/tex]
[tex]\[ b = \frac{d \cdot \tan(\angle_1)}{\tan(\angle_2) - \tan(\angle_1)} \][/tex]
Substituting in the values:
[tex]\[ b = \frac{1200 \cdot 0.7002075382097097}{0.9004040442978399 - 0.7002075382097097} = -4197.121429690478 \, \text{feet} \][/tex]

5. Calculate the height [tex]\(h\)[/tex]:
Using [tex]\(h = b \cdot \tan(\angle_2)\)[/tex]:
[tex]\[ h = -4197.121429690478 \cdot 0.9004040442978399 = -3779.1051097024388 \, \text{feet} \][/tex]

### Height of the mountain:

Thus, the height of the mountain is approximately [tex]\( -3779.11 \)[/tex] feet.

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