Moe is playing with a yo-yo. He throws the yo-yo down and then pulls it back up. The motion of the yo-yo is represented by the equation y=2x^2−4.8x
, where x represents the number of seconds since the yo-yo left Moe's hand, and y represents the vertical height in inches of the yo-yo with respect to Moe's hand. Note that when the yo-yo is in Moe's hand, y = 0, and when the yo-yo is below his hand, y is negative. a. How long is Moe's yo-yo in the air before it comes back to Moe's hand? Write and solve a quadratic equation to find the times that the yo-yo is in Moe's hand. b. How long does it take for the yo-yo to turn around, that is, to start its return to his hand? Use what you know about parabolas to help you. c. How long is the yo-yo's string? That is, what is y when the yo-yo changes direction? d. Draw a sketch of the graph representing the motion of Moe's yo-yo. On the sketch, label the important points: when the yo-yo is in Moe's hand and when it changes direction.