Question

Q4. Given y = ax2 + bx + c (where a, b,c E R), find the values of a, b and c
if the graph of the given equation passes through the points (-1,9), (1,5) and
(2, 12).​

Answer 1

Answer:

Since parabola is upward a>0

Curve is crossing x-axis at two points ⇒ roots are real ⇒b

2

−4ac>0

Roots are of opposite signs c/a<0⇒c<0

Also magnitude of +ve root is larger ⇒ sum of roots >0

⇒−b/a>0⇒b<0

Hence all the options are correct.