Standard Form: Using the Formula Method
- #7-17odd (using graphing calculator to compare)
So now that we know a little bit about how "a", "b", and "c" effect the graph of a parabola in standard form, lets actually graph some functions by using the formula method.
Step 1 - Identify the numeric values a, b, and c.
a = -1
b = -12
c = 4
Step 2 - Use the formula below to find the x-value of the vertex, which is the same as the axis of symmetry.
Vertex (-6, ?)
AOS x = -6
Step 3 - Find the y-value of the vertex by plugging in the x-value into the equation.
Vertex (-6, 40)
Step 4 - Plug in points into table and graph.
Step 5 - Roughly plot the points from table and sketch graph.