Foundations
Foundations
Graphing a Quadratic
Example
Graph the quadratic equation y = 2x2 ? 8x + 6.
Step 1. Determine a, b and c and decide if the graph will open up or down.
a = 2, b= -8, and c = 6. Because a is positive, the graph will open upward.
Step 2. Find the vertex.
The vertex is at the point (2, -2)
Step 3. Find the x-intercepts.
To find the x-intercepts, substitute 0 in for the y and solve. This was covered completely in the solving book.
2x2 ? 8x + 6 = 0
2(x2 - 4x +3) = 0
2(x - 1)(x -3) = 0
x = 1 or x = 3
The x-intercepts are (1,0) and (3,0).