If we were to try to solve Devyn's coffee problem, what would be the best function to know? {{CMD_13}} {{CMD_14}}How many donuts Devyn eats.{{CMD_15}} {{CMD_16}}How ``good'' Devyn feels after {{MATH_17}} cups of coffee.{{CMD_18}} {{CMD_19}}How many cups of coffee Devyn drinks when Devyn feels {{MATH_20}} ``good.''{{CMD_21}} {{CMD_22}}Impossible to say.{{CMD_23}} {{CMD_24}} {{CMD_25}} If we let {{MATH_26}} be ``How `good' Devyn feels after {{MATH_27}} cups of coffee,'' and we think about what Devyn says above, is there an amount Devyn can drink and feel maximally ``good?'' {{CMD_28}} {{CMD_29}}yes{{CMD_30}} {{CMD_31}}no{{CMD_32}} {{CMD_33}} {{CMD_34}} ``Yes'' is probably the best answer, though we are assuming that Devyn feels ``bad'' without enough coffee, ``good'' with some, and ``bad'' again with the function continuously growing and then decreasing. {{CMD_35}} {{CMD_36}} {{CMD_37}}