Which of the sets of ordered pairs represents a function?
a = {(1, −2), (3, −5), (5, 2), (7, 5)}
b = {(4, 2), (4, −2), (9, 3), (9, −3)}
only a
only b
both a and b
neither a or b

The motion of a weight that hangs from a spring is represented by the equation h=8sin(2pi/3t). it models the weight’s height above or below the rest position as a function of time. approximately when will the object be 3 inches above the rest position?