JAMB - Mathematics (1991 - No. 33)
A flagstaff stands on the top of a vertical tower. A man standing 60 m away from the tower observes that the angles of elevation of the top and bottom of the flagstaff are 64o and 62o respectively. Find the length of the flagstaff.
60 (tan 62o - tan 64o)
60 (cot 64o - cot 62o)
60 (cot 62o - cot 64o)
60 (tan 64o - tan 62o)
Giải thích
\(\frac{BC}{60}\) = \(\frac{tan 62}{1}\)
BC = 60 tan 62
\(\frac{AC}{60}\) = \(\frac{tan 62}{1}\)
AC = 60 tan 64
AB = AC - BC
= 60(tan 64o - tan 62o)
BC = 60 tan 62
\(\frac{AC}{60}\) = \(\frac{tan 62}{1}\)
AC = 60 tan 64
AB = AC - BC
= 60(tan 64o - tan 62o)