Question

Please help, i forgot which was which... (positive or negative coefficient)

19b
Is the coefficient of x^(2) in the quadratic function positive or negative?
(image included)

Answer 1

Answer: Negative

Reason:

The template
`y = ax^2+bx+c` applies to any quadratic to graph out a parabola. The coefficient for the x^2 term is 'a', and it solely determines whether the parabola opens upward or downward.

If 'a' is negative, then the parabola opens downward. The way to remember this is that 'a' being negative forms a negative frown.

On the other hand if 'a' is positive, then it forms a positive smile, and the parabola opens upward.

In this case, the points are fairly close to a parabola opening downward. This means 'a' is negative and a < 0.