Quadratic equations can be represented in three main forms: factored form, vertex form, and standard form. Each form offers unique insights and methods for solving quadratic equations.
Use FOIL
(multiply firsts, outsides, insides and lasts)
Find vertex
Using the zeros, find AoS (x-value of vertex) with the formula: (r+s)/2
Zeros are the value of r and s but the opposite signs (if r was negative, the zero would be positive, if r was positive the zero would be negative. Same applies to value s)
Substitute the AoS (for value x) in factored form to get K (y-value of vertex)
When you have the vertex and are writing the vertex form. The x-value (AoS) will be the opposite sign (if it is -, in the equation it will be +. If it is +, in the equation it will be -). The y-value stays the same. h = x-value of vertex and k = y-value of vertex
Example
y = (x-2)(x+6)
AoS = (r+s)/2
= (2-6)/2
= -4/2
=-2
Substitute -2 into factored form to get K
Y = 1(-2-2)(2+6)
Y = 1(-4)(8)
Y = -16
Vertex: (-2,-16)