Two observers are stationed due north of a tower (of height x meter) a...
In triangle ABC
tan∠ACB = AB/BC
⇒ tan45° = x/BC
⇒ 1 = x/BC
⇒ x = BC
In triangle ABD
tan∠ADB = AB/BD
⇒ tan30° = x/BD
⇒ 1/√3 = x/BD
⇒ BD = x√3
CD = BD – BC
⇒ y = x(√3 – 1)
⇒ y(√3 + 1) = x × (√3 – 1) × (√3 + 1)
⇒ y(√3 + 1) = x × (3 – 1) [∵ (a – b) (a + b) = a2 – b2]
⇒ y(√3 + 1) = 2x
∴ x/y = (√3 + 1) /2
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Two observers are stationed due north of a tower (of height x meter) a...
Let the height of the tower be x meters and the distance between the observers be y meters.
From the first observer's position, the angle of elevation to the top of the tower is 30 degrees. This forms a right-angled triangle with the height of the tower, the distance from the observer to the base of the tower, and the line of sight to the top of the tower.
Therefore, we can write:
tan(30 degrees) = x / y
1/sqrt(3) = x / y
y = sqrt(3) * x
Similarly, from the second observer's position, the angle of elevation to the top of the tower is also 30 degrees. This forms another right-angled triangle with the height of the tower, the distance from the second observer to the base of the tower, and the line of sight to the top of the tower.
Therefore, we can write:
tan(30 degrees) = x / (y + d)
1/sqrt(3) = x / (sqrt(3) * x + d)
1/sqrt(3) = 1 + d / sqrt(3) * x
d = (sqrt(3) - 1) * x
So, the distance between the two observers is (sqrt(3) - 1) * x meters.