Trigonometryhard · Past Paper
A vertical tower is surmounted by a flagstaff of height h. At a point on ground, elevations of bottom and top of flagstaff are α and β. Tower height is:
Ah tanα / (tanβ - tanα)
Bh tanβ / (tanβ - tanα)
Ch / (tanβ - tanα)
Dh tanα tanβ
✓ Correct Answer: A — h tanα / (tanβ - tanα)
H/d = tan α, (H+h)/d = tan β. H/tan α = (H+h)/tan β. H tan β = H tan α + h tan α. H = h tan α / (tan β - tan α).
Share this question
More from Trigonometry
- If sin A + cos A = m, then sin 2A is:
- What is the value of sin 18°?
- The angles of elevation of the top of a tower from two points on the ground at distances 4 m and 9 m from the base are complementary. Tower height?
- Simplify: (cos A - sin A)(cos A + sin A).
- Simplify: sin(A-B)/cos A cos B + sin(B-C)/cos B cos C + sin(C-A)/cos C cos A.