Question

Explain how you know if the graph of a quadratic function will open up or down. ax^2+bx+c

Answer 1

Graphing Quadratic Functions
There is an easy way to tell whether the graph of a quadratic function opens upward or downward: if the leading coefficient is greater than zero, the parabola opens upward, and if the leading coefficient is less than zero, the parabola opens downward.
Source: sparknotes.com
https://www.sparknotes.com/math/precalc/polynomialfunctions/section2/