[ Homework Help ] Open Question : I’m confused what I am doing wrong. I have to “create a table of values and an associated graph that are decreasing and concave down.”?

Hello I am currently working on a problem my prof. assigned and I’m confused what I am doing wrong. I have to “create a table of values and an associated graph that are decreasing and concave down.” How do I find the missing ? in the y’s? x y 1 49 2 ? 3 43…