Two poles X and Y stand 3√2 m apart, such that the angle of elevation of the top of pole X as observed from the foot of pole Y is 30° and the angle of elevation of the top of pole Y as observed from the top of pole X is 60°. What is the angle of elevation of the top of pole Y from the foot of pole X?
Two poles X and Y stand 3√2 m apart, such that the angle of elevation of the top of pole X as observed from the foot of pole Y is 30° and the angle of elevation of the top of pole Y as observed from the top of pole X is 60°. What is the angle of elevation of the top of pole Y from the foot of pole X? Correct Answer tan<sup>- 1</sup> (4/√3)
Given:
distance between poles = XY = AC = 3√2 m
Formula Used:
tan θ = perpendicular/base
Calculation:
Let A and B be the top of poles X and Y respectively, as shown below,
Let θ be the angle of elevation of top of pole Y as observed from foot of pole X,
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Given, distance between poles = XY = AC = 3√2 m
Considering ∆AXY,
⇒ tan 30° = perpendicular/base = AX/XY
⇒ 1/√3 = AX/3√2
⇒ AX = 3√2/√3 = √6 m
Considering ∆ ACB,
⇒ tan 60° = perpendicular/base = BC/AC
⇒ √3 = BC/3√2
⇒ BC = 3√6 m
⇒ BY = BC + CY = BC + AX = 3√6 + √6 = 4√6 m
Now,
Considering ∆XYB,
⇒ tan θ = perpendicular/base = BY/XY
⇒ tan θ = 4√6/3√2
⇒ tan θ = 4/√3
∴ Required angle = θ = tan- 1 (4/√3)