PLEASE HELPBRAINLIEST PLUS 50 POINTS y = −5x2 + 10x + 12.

Part A: Show your work to complete the square of the function. (1 point)

Part B: Identify the vertex of the function. (1 point)

Part C: Explain how to determine the maximum or minimum value of the function. (2 points)

Use the quadratic formula to find:

x

=

1

±

√

85

5

Explanation:

5

x

2

−

10

x

−

12

is of the form  

a

x

2

+

b

x

+

c

with  

a

=

5

,  

b

=

−

10

and  

c

=

−

12

This has discriminant  

Δ

given by the formula:

Δ

=

b

2

−

4

a

c

=

(

−

10

)

2

−

(

4

×

5

×

−

12

)

=

100

+

240

=

340

=

2

2

⋅

85

This is positive, but not a perfect square, so the quadratic equation has a pair of irrational roots, given by the quadratic formula:

x

=

−

b

±

√

b

2

−

4

a

c

2

a

=

−

b

±

√

Δ

2

a

=

10

±

√

340

10

=

10

±

2

√

85

10

=

1

±

√

85

5