When does a parabola open upward?

Anonymous
0
Recall what is a quadratic function
A quadratic function is one of the form f(x) = ax2 + bx + c, where a, b, and c are numbers with a not equal to zero.
In general the graph of a quadratic function is a parabola.
If a>0, the parabola has a minimum point and the graph opens upward. The parabola is U shaped. For example y = 2x^{2} +3x +2
If a < 0, then the parabola has a maximum point and it opens downwards (n-shaped) eg. -2x^{2}+3x+2