# How can I tell whether a parabola opens upward or downward?

The highest order term, the coefficient of the ${x}^{2}$ term, will tell you. Or, graphically, if it looks like a bowl instead of a mountain.
If the term is positive, then as ${x}^{2}$ dominates the $x$ term with bigger values of $| x |$, the result of the equation will become bigger and bigger.