### Home > PC3 > Chapter 4 > Lesson 4.2.2 > Problem 4-80

4-80.

Demarre and Alaysha are trying to decide where the graph of , but Alaysha says that it can not be concave up for

*since the function is decreasing. Demarre says that it does not matter; all that matters is that it curves up. Who is correct? Explain your answer.*

A curve is concave up where it can be sketched as a portion of a "cup that is right side up".