So second, and I want to select that up there, so I'll do graph. And it looks like we did get the right range. So this tells us volume is a function of x between x is 0 and x is 10. And it does look like we hit a maximum point right around there. So what I'm going to do is I'm going to use the trace function to figure out roughly what that maximum point is. So let me trace this function so I can still go higher, higher. So over there my volume is 1055.5.