Question 3 Two balls A and B were Initially 9 m apart. Ball A moved at a speed of v A = 2 m/s and ball B moved at a speed of up = 4 m/s in the directions as shown in the figure below. I point B Find the rate of change (in m/s) of the distance between A and B after they moved for 7 s. Express your answer in exact form without the units. (Note: When you input a square root, use sqrt(x) or VI instead of z (0.5), Question 4 A cone-shaped water tank with height H = 6 m and radius R = 3 m is as shown in the figure below. Water is leaking at a rate of a mo /s through a small hole at the bottom of the tank. How fast was the depth of water decreasing (in m/s) when the depth of the water is 3 m. 1 point H Water R Express your answer in exact form without the units. Question 5 Let x and y be two non-negative real numbers and r + y = 12. Find the maximum value of zy. 1 point Answer : Question 10 Let (1 : y = mix + cj and 62 : y = max + cy be the tangent lines to the circle x2 + y2 = 49 and both tangent lines pass through the point (0, 21). Find the product of m1 and m2- 1 point (Hint: Find the two points where tangent lines touches the circles first. Note that he point (0, 21) is not on the circle x2 + y2 = 49.)