Question

X 5.2.19

Find the quadratic function y = ax2 + bx+c whose graph passes through the given points.
(-2,-27), (3, - 42), (1, -12)
y =

Answer 1

Explanation:

y = ax² + bx + c

Plug the points into the equation to get a system of 3 equations with 3 unknowns a, b, and c.

-27 = 4a - 2b + c

-42 = 9a + 3b + c

-12 = a + b + c

(a,b,c) = (-4,1,-9)

y = -4x² + x - 9