Find a quadratic function that includes the set of values below. (0,8), (2,16), (4,0)
The equation of the parabola is y =

Let y=ax^2+bx+c be the equation of the parabola. Set up equations.

Using (0,5). 5=a(0)2+b(0)+c

5

=

a

(

0

)

2

+

b

(

0

)

+

c

Using (2,15), 15=a(2)2+b(2)+5

15

=

a

(

2

)

2

+

b

(

2

)

+

5

4a+2b=10

2a+b=5

Using (4,9)

9=a(4)2+b(4)+5

9

=

a

(

4

)

2

+

b

(

4

)

+

5

16a+4b=4

4a+b=1

Subtract each side of (1) and (2) to eliminate b and solve for a: -2a=4

a=-2

Solve for b using (1): 2(-2)+b=5

-4+b=5

b=9

So, the equation is y=−2x2+9x+5

Step-by-step explanation: