Which relation is a function? A. (1, 0), (3.0), (1.1), (3, 1) (1.3)
B. (1, 1), (2, 2), (3, 3), (4, 4). (5, 8). C. ( 2, 7), (6,5), (4.4), (3, 3), (2, 1)
D. (9. -3), (19, 3) (4, -2), (4, 2), (0, 0)

people went from manufacturing one object at a time by hand to manufacturing many objects in factories

f(x) = x^3 -2x^2 -3x

x( x^2 -2x-3)

x( x^2 +x -3x -3)

x( x(x+1) -3(x+1))

x( x-3)( x+1)

so zeroes are 0, 3,-1

its (2) option