Answer:
x = 40/21
Step-by-step explanation:
This should be the right answer...
Answer:
The height above sea level at <em>B</em> is approximately 1,604.25 m
Step-by-step explanation:
The given length of the mountain railway, AB = 864 m
The angle at which the railway rises to the horizontal, θ = 120°
The elevation of the train above sea level at <em>A</em>, h₁ = 856 m
The height above sea level of the train when it reaches <em>B</em>, h₂, is found as follows;
Change in height across the railway, Δh = AB × sin(θ)
∴ Δh = 864 m × sin(120°) ≈ 748.25 m
Δh = h₂ - h₁
h₂ = Δh + h₁
∴ h₂ ≈ 856 m + 748.25 m = 1,604.25 m
The height above sea level of the train when it reaches <em>B</em> ≈ 1,604.25 m
The area and perimeter of the triangle is 2/5 square units and (2√10 + 4√5) / 5 units
<h3>Determining the perimeter and area of the triangle giving line equation</h3>
In order to determine the area and perimeter of the lines, we will plot the giving lines, determine the point of intersection and then use the Pythagoras theorem to determine the dimension of the right triangle.
The points of intersection of the line are;
(x₁, y₁) = (- 0.4, 5.2),
(x₂, y₂) = (-0.8, 4.4),
(x₃, y₃) = (0, 4)
Determine the base
b² = c² -a²
b = √(-0.8)² + (4 - 4.4)²
b = 2√5 / 5
Determine the height
h = √((- 0.4) - (- 0.8))² + (5.2 - 4.4)²
height = 2√5 / 5
For the hypotenuse
r = √2 · b
r = 2√10 / 5
<h3>Determine the Perimeter and area</h3>
Perimeter = s1+s2+s3
Perimeter = 2√5 / 5 + 2√5 / 5 + 2√10 / 5
Perimeter = (2√10 + 4√5) / 5 units
<u>For the area</u>
area = 1/2* base * height
A = 0.5 · (2√5 / 5) · (2√5 / 5)
A = 2/5 square units
Hence the area and perimeter of the triangle is 2/5 square units and (2√10 + 4√5) / 5 units
Learn more on area and perimeter of triangles here: brainly.com/question/12010318
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Answer:
-499,485.
Step-by-step explanation:
We can transform this to an arithmetic series by working it out in pairs:
6^2 - 7^2 = (6-7)(6+7) = -13
8^2 - 9^2 = (8-9)*8+9) = -17
10^2 - 11^2 = -1 * 21 = -21 and so on
The common difference is -4.
The number of terms in this series is (998 - 6) / 2 + 1
= 992/2 + 1 = 497.
Sum of n terms of an A.S:
= n/2 [2a1 + (n - 1)d
Here a1 = -13, n = 497, d = -4:
Sum = (497/2)[-26 - 4(497-1)]
= 497/2 * -2010
= -499,485.