Q A hunter walking at the rate of 2 ft/see down a hill inclined at E- radian with the horizontal saw a bird on a tree situated down the hill. If the hunter's eye is 6 ft above the ground and the bird is 5 ft above the ground, how fast is the angle of depression of the bird from the hunter's eye changing at an instant when the hunter is 10 ft from a point on the ground directly below the bird