A man on the top of a tower, standing on the sea-shore, finds that a boat coming towards him takes 10 minutes for the angle of depression to change from 300 to 600. How soon the boat reach the sea-shore
A vertical tower stands on a horizontal plane and is surmounted by a vertical flag staff of height h. At a point on the plane, the angle of elevation of the bottom of the flag staff is a and that of the top of the flag staff is β. Then the height of the tower is
From the top of a cliff 100 metre high, the angles of depression of the top and bottom of a tower are 450 and 600 respectively. The height of the tower is
If 2ycos θ = xsin θ and 2xsec θ - ycosec θ = 3, then the value of x2 + 4y2 is
A person from the top of a hill observes a vehicle moving towards him at a uniform speed. It takes 10 minutes for the angle of depression to change from 450 to 600.
After this the time required by the vehicle to reach the bottom of the hill is
If (a2-b2) sin θ + 2abcos θ = a2+b2, then tan θ =