QUESTION 4 A person 2 m tall walks towards a lamppost on level ground at a rate of 0.6m/sec. The lamp on the post is 6m high. At which rate the length of the person's shadow decreasing when the person is 3m from the post? Please enter your answer in decimal format with three significant digits after the decimal point. QUESTION 5 A person 1.85 m tall walks towards a lamppost on level ground at a rate of 0.6 m/sec. The lamp on the post is 5 m high. At which rate the tip of the person's shadow moves toward the lamppos when the person is 4m from the post? Please enter your answer in decimal format with three significant digits after the decimal point. QUESTION 6 Find the differential dy for f (x) = 20 In V1 + x2 and evaluate it for a = 2 and da = 0.1. Please enter your answer in decimal format with three significant digits after the decimal point