parabola opening?

Question

When does a parabola open upward and when does a parabola open downward?

Answer 1

If the coefficient of the x^2 term is positive, you have a cup up parabola (opens up).

If the coefficient is negative, you have a cup down parabola (opens down)

Hope this helps. :)

Answer 2

Let us consider y=A(x^2)
x^2 is always +ve.So if A is +ve then y is +ve.
If A is +ve, y is +ve & parabola is upward.
If A is -ve ,y is -ve ¶bola is downward.