SOLUTION: y = -x^2 + 7x - 2 I need to graph this quadratic function. I know I will need to use -b/2a and find y, but I am quite confused on how to solve this problem.

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: y = -x^2 + 7x - 2 I need to graph this quadratic function. I know I will need to use -b/2a and find y, but I am quite confused on how to solve this problem.       Log On


   

Question 250613: y = -x^2 + 7x - 2
I need to graph this quadratic function.
I know I will need to use -b/2a and find y, but I am quite confused on how to solve this problem.
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
x=-b%2F2a will give you the vertex and the axis of symmetry.
b=7
a=-1
x=-7%2F2=3.5
You can then plot points equidistant from the vertex (they have the same y value).
x=3 and x=4 would give the same y, y=-9+21-2=10
x=2 and x=5 would give the same y, y=-4+14-2=8
x=1 and x=6 would give the same y, y=-1+7-2=4
x=0 and x=7 would give the same y, y=0+0-2=-2