A survey team is trying to estimate the height of a mountain above a level plain. From one point on the plain, they observe that
the angle of elevation to the top of the mountain is 31. From a point 1000 feet closer to the mountain along the plain, they find that the angle of elevation is 34. How high (in feet) is the mountain?
1 answer:
Answer:
5507.79 feet
Step-by-step explanation:
To find the height of the mountain, we can draw triangles as in the image attached.
Let's call the height of the mountain 'h', and the distance from the first point (31 degrees) to the mountain 'x'.
Then, we can use the tangent relation of the angles:
tan(34) = h/x
tan(31) = h/(x+1000)
tan(31) is equal to 0.6009, and tan(34) is equal to 0.6745, so:
h/x = 0.6745 -> x = h/0.6745
using this value of x in the second equation:
h/(x+1000) = 0.6009
h/(h/0.6745 + 1000) = 0.6009
h = 0.6009 * (h/0.6745 + 1000)
h = 0.8909*h + 600.9
0.1091h = 600.9
h = 600.9 / 0.1091 = 5507.79 feet
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Answer:
The lines L1 and L2 neither parallel nor perpendicular
Step-by-step explanation:
* Lets revise how to find a slope of a line
- If a line passes through points (x1 , y1) and (x2 , y2), then the slope
of the line is
- Parallel lines have same slopes
- Perpendicular lines have additive, multiplicative slopes
( the product of their slopes is -1)
* Lets solve the problem
∵ L1 passes through the point (1 , 10) and (-1 , 7)
- Let (1 , 10) is (x1 , y1) and (-1 , 7) is (x2 , y2)
∴ x1 = 1 , x2 = -1 and y1 = 10 , y2 = 7
∴ The slope of L1 is
∵ L2 passes through the point (0 , 3) and (1 , 5)
- Let (0 , 3) is (x1 , y1) and (1 , 5) is (x2 , y2)
∴ x1 = 0 , x2 = 1 and y1 = 3 , y2 = 5
∴ The slope of L2 is
∵ m1 = 3/2 and m2 = 2
- The two lines have different slopes and their product not equal -1
∴ The lines L1 and L2 neither parallel nor perpendicular