Question

Use quadratic regression to find

Answer 1

Answer:

y = 6x² -13x -5

Step-by-step explanation:

(1,-12) (2,-7) (5,80)

y = ax² + bx + c

-12 = a*1² + b*1 + c = a+b+c    (1)

-7 = 4a + 2b + c    (2)

80 = 25a + 5b + c   (3)

(2)-(1): 3a + b = 5    (4)

(3)-(2): 21a + 3b = 87   (5)

(4)*3:     9a + 3b = 15    (6)

(5)-(6):  12a = 72      a = 6

(4)                             b = -13

(2)                             c = -5