In which set of points is y a function of x? A. {(1, 4), (2, 7), (1, 10), (3, 13)}
B. {(0, 0), (1, 1), (2, 2), (2, -2)}
C. {(0, -6), (1, -8), (2, -10), (3,-6)}
D. {(10, 20), (20, 40), (20, 80), (40, 80)}

answer:   c ?

step-by-step explanation:

b, 20 yards

step-by-step explanation:

h is the x-coordinate of the vertex

step-by-step explanation:

we have

in this function

the point represent the vertex of the function

so

h is the x-coordinate of the vertex

k is the y-coordinate of the vertex