The image of quadratic function y = ax ^ 2 + C passes through points a (1, - 3), B (- 2, - 6) Find this first-order function

The image of quadratic function y = ax ^ 2 + C passes through points a (1, - 3), B (- 2, - 6) Find this first-order function

Substituting x = 1, y = - 3 into the original function: a + C = - 3 ----- 1
Substituting x = - 2, y = -- 6 into the original function: 4A + C = - 6 ----- 2
If 2 minus 1, 3A = - 3, a = - 1
Substituting into 1, C = - 2
So this linear function is: y = - X & # 178; - 2

If the parabola y = ax ^ 2 + BX + C (a is not equal to 0) intersects the x-axis with (x1,0) (x2,0), and x10
B ^ 2-4ac is greater than or equal to 0
C X1

A can't judge, because it has two intersections with the X axis, so B ^ 2-4ac > 0, C option is not necessarily, you can spend it on the grass paper
The answer is d