What is the Purpose of this Text Box?

On the graphing calculator 3d, there is a text box in the upper left corner, just under the toolbar, and just above and slightly to the left of the equation editing (z=) text boxes. It also has a check box to the left of it, but no z= to it's left. I tried typing an equation into it, but it always gives an error of n/a to the right. I can't find any documentation on this. Can you tell me what it's purpose is?

Another question - when will implicit equations be supported? Thanks!

It's just a blank line that you probably inserted by mistake. If it doesn't have z= in front of it then it must be just a math solver where you can type for example 5+3 and get 8 in front of it as answer.

You can simply delete it by clicking on it first and then click Delete [-] on the toolbar.

cheers