Answer: You will need to find the x-intercepts and the vertex
Step-by-step explanation: Use the information in the factors and some formulae.
The x- intercepts are the points where the parabola crosses the x-axis. The x-axis is where y = 0
Set each factor equal to 0 and solve:
x-2=0, so x = +2 and x +4 = 0, so x = -4 (you would plot these if creating the graph)
To find the vertex you need the Vertex Formula: x = -b/2a
b is the coefficient of the x term in the middle of the quadratic equation; you can just do the O and I parts of FOIL to get b: -2x + 4x = 2x You know a = 1 because x² will have the implied (missing)(1).
Put the numbers in the Formula: x = -b/2a x = -(2)/2(1) -2/2 = -1
-1 is the "x-value" of the vertex.
The y value is the 'c' in the quadratic formula. You get that from the L part of FOIL -2 × 4 = -8 .
So, your coordinates for the vertex: ( -1, -8 )
If you were creating a graph, you would plot that point, then draw the parabola starting there and through the x-intercepts.
