Question
From the top of a lighthouse 75 feet high, the cosine of the angle of depression of a boat out
at sea is 4. To the nearest foot, how far is the boat from the base of the lighthouse?
at sea is 4. To the nearest foot, how far is the boat from the base of the lighthouse?
Answers
Henry
The cosine can't be greater than 1.
Henry
cosA = 0.4,
A = 66.4 deg.
tan66.4 = 75 / d,
d = 75 / tan66.4 = 33 Ft.
A = 66.4 deg.
tan66.4 = 75 / d,
d = 75 / tan66.4 = 33 Ft.