Word problem with curving of graphs

[LinBOM (Linus)]

I’ve just started learning about the second derivative and I find it very peculiar that we in norwegian say that the hollow side faces up/down as an answer to how the graph curves. Do you really say it like this in English? (or any other language I suppose)

 

[HallsofIvy]

We would say that the graph is "concave upward" or "concave downward". A curve is "concave upward" if every point on the line segment between any two given points on the curve is above the curve.