question_answer

A flag - staff is fixed at the top of a tower. The angles of elevation of the top and the bottom of this flag-staff at a point distant 'a' m from the foot of the tower, are\[\alpha \]and\[\beta \], respectively. Find the height of the flag -staff (in m).

A) \[a(\sin \alpha -\sin \beta )\]

B)        \[a(\cos \beta -\cos \alpha )\]

C) \[a(\tan \alpha -\tan \beta )\]

D)        \[a\tan (\alpha -\beta )\]