Question

a man on a cliff observes a boat at an angle of depression of 30 degree which is approaching the shore to the point immediately beneath the observer with a uniform speed. six minutes later, the angle of depression of the boat is found 60 degree. find the total time taken by that boat to reach the shore.

Answer 1

here is your answer which you want

Answer 2

According to question, the man is standing at some height and just below him the shore is situated.

From that height he she sees a boat with an angle of elevation of 30° which increases after 6 minutes (comes nearer).

Since for Trignometery we need "distance" hence d = vt.

• Let the height of tower be h.

• tan30° = 1/√3 and tan60° = √3.

• We have obtained a right ∆, so use Trignometeric Identities.

Solution is given in attachment