What is vertex form?

Vertex form makes the vertex of the parabola easy to see.

General form:

f(x) = a(x – h)^2 + k

Where:

• (h,k) is the vertex

• a controls opening direction and width

How to read vertex form

Example:

f(x) = 2(x – 3)^2 + 1

• Vertex: (3,1)

• Opens up (because a=2>0)

• Narrower than y = x^2

Why vertex form is useful

Vertex form is best for:

• Finding the maximum or minimum value

• Graphing quickly

• Understanding transformations

Comparing forms