Question

Equation for parabola that has points (-4,2) (0,2) (-2,3)

Answer 1

Step-by-step explanation:

What is the equation of the parabola that has a vertex at

(

−

4

,

2

)

and passes through point

(

−

7

,

−

34

)

?

To solve this you need to use the vertex form of the equation of a parabola which is

y

=

a

(

x

−

h

)

2

+

k

, where

(

h

,

k

)

are the coordinates of the vertex.

Explanation:

The first step is to define your variables

h

=

−

4

k

=

2

And we know one set of points on the graph, so

x

=

−

7

y

=

−

34

Next solve the formula for

a

y

=

a

(

x

−

h

)

2

+

k

−

34

=

a

(

−

7

+

4

)

2

+

2

−

34

=

a

(

−

3

)

2

+

2

−

34

=

9

a

+

2

−

36

=

9

a

−

4

=

a

To create a general formula for the parabola you would put in the values for

a

,

h

, and

k

and then simplify.

y

=

a

(

x

−

h

)

2

+

k

y

=

−

4

(

x

+

4

)

2

+

2

y

=

−

4

(

x

2

+

8

x

+

16

)

+

2

y

=

−

4

x

2

−

32

x

−

64

+

2

So the equation of a parabola that has a vertex at

(

−

4

,

2

)

and passes through point

(

−

7

,

−

34

)

is:

y

=

−

4

x

2

−

32

x

−

62