How do you graph #y=x^2- 6x + 8# by plotting points?

1 Answer
Apr 18, 2018

"a" is positive = parabola pointing up
"a" is negative = parabola pointing down

First point:
Vertex x-coordinate = -b/2a
plug that answer back into the equation for "x" and then find "y"
(x,y) is the first coordinate

  • set "y" to zero = get x-intercept (use factoring or quadratic equation)
  • set "x" to zero = get y-intercept(s)
  • make a t-chart with "x" on one side and "y" on the other.
    Think of any "x" coordinate and then plug it into the equation to solve for the "y" coordinate.