The graphs of quadratic functions are called parabolas. Here are some examples of parabolas. All parabolas are vaguely “U” shaped and they will have a highest or lowest point that is called the vertex. Parabolas may open up or down and may or may not have x -intercepts and they will always have a single y -intercept.
The graph of a quadratic function is a U-shaped curve called a parabola. The sign on the coefficient a of the quadratic function affects whether the graph opens up or down. If a<0 , the graph makes a frown (opens down) and if a>0 then the graph makes a smile (opens up).
Credits:
Graphs of Quadratic Functions | Boundless Algebra - Lumen Learning
