Question

At a distance a from the foot of a tower AB of height b,a flag staff BC and the tower AB subtend equal angles. Prove that the height of the flag staff is b(a^2+b^2)/a^2-b^2.​

Answer 1

Answer:

a

b

=tanθ,

a

b+x

=tan2θ

or

a

b+x

=

1−tan

2

θ

2tanθ

=

1−

a

2

b

2

2.

a

b

a

b+x

=

a

2

−b

2

2ab

∴x=

a

2

−b

2

2a

2

b

−b

or x=

a

2

−b

2

a

2

b+b

3

=

a

2

−b

2

b(a

2

+b

2

)