Question

A tower is b ft. high having a flag staff at its top. The tower and the flag staff subtend equal angles at a point distant a feet from the foot of the tower. Then the length of flag staff is______

Answer 1

$\frac{b(a^2+b^2)}{(a^2-b^2)}$
t = tan $\theta$ = b/a, tan 2$\theta$ = b + x/a = 2t/1 + $t^2$
$\therefore$ x = etc.