Question

PLEASE HELP!!

Fit a Quadratic function to these three points: (-1,-11), (0,-3) and (3,-27)

A. y=-4x^2+ 4x- 3

B. y=4x^2- 4x- 3

C. y=-4x^2 - 4x + 3

D. y=-4x^2- 4x-v3

Answer 1

We can do the same thing that we did last time to solve this one.

For A. (-1,-11):

`y = - 4 {x}^(2) + 4x - 3 \\ ( - 11) = - 4 {( - 1)}^(2) + 4( - 1) - 3 \\ - 11 = - 4 - 4 - 3 \\ - 11 = - 11`
For A. (0,-3):

`( - 3) = - 4 {(0)}^(2) + 4(0) - 3 \\ - 3 = - 3`
For A. (3,-27):

`( - 27) = - 4 {(3)}^(2) + 4(3) - 3 \\ - 27 = - 36 + 12 - 3 \\ - 27 = - 27`
A. is the answer, but we need to double-check.


For B. (-1,-11):

`y = 4 {x}^(2) - 4x - 3 \\ ( - 11) = 4 {( - 1)}^(2) - 4( - 1) - 3 \\ - 11 = 4 + 4 - 3 \\ - 11 = 5`
For C. (0,-3):

`y = - 4 {x}^(2) - 4x + 3 \\ ( - 3) = - 4 {(0)}^(2) - 4(0) + 3 \\ - 3 = 3`
For D. (-1,-11):

`y = - 4 {x}^(2) - 4x - 3 \\ ( - 11) = - 4 {( - 1)}^(2) - 4( - 1) - 3 \\ - 11 = - 4 + 4 - 3 \\ - 11 = - 3`
Since none of the other answers are correct, the answer is A.