25.1k views
1 vote
Can somebody explain to me how to find vertex form from a graph?? I put an example graph if you need it :)))

Can somebody explain to me how to find vertex form from a graph?? I put an example-example-1
User Rory Hart
by
4.2k points

1 Answer

5 votes

Answer:

y = - 4(x + 3)² + 7

Explanation:

The equation of a parabola in vertex form is

y = a(x - h)² + k

where (h, k) are the coordinates of the vertex and a is a multiplier

From the graph (h, k ) = (- 3, 7 ), thus

y = a(x + 3)² + 7

To find a we require a point on the graph other than the vertex

Using (- 2, 3) , substitute into the equation

3 = a(- 2 + 3)² + 7

3 = a + 7 ( subtract 7 from both sides )

a = - 4

Thus

y = - 4(x + 3)² + 7 ← in vertex form

User Amine Jallouli
by
5.7k points