Question

Which equation has this graph?

Answer 1

A. y = x2 - 6x + 5
B. y = -x2 - 6x + 5
C. y = -x2 - 6x - 5
D. y = x2 + 6x - 5

Answer 2

well it's
y = x^2
its going upwards, thus must be positive (not -x^2) thus only A/D

and the real clincher

it has points along the x-axis or "roots" at (1,0) and (5,0)

if we factor A and D:

A: (x-5)(x-1) -> x = 5,1
D: not factorable

We see that A is the only viable answer that meets all three criteria: direction, shape, and location of roots.

Answer 3

thankyou very much!