Leave superscript mode in Mac Grapher Mac Grapher has is a keyboard shortcut for entering superscripts: use the ^ key.  For instance, you can type x^2 to get the expression x2.

Once I've entered superscript mode, how do I leave superscript mode?  For instance, if I want to enter in the expression x2 + 3, what do I type?  If I type the characters x^2 + 3 on the keyboard, I get the expression x2 + 3, which is not what I wanted.

I couldn't find any description of this in the help pages for Grapher.
You can use down arrow ↓ or right arrow → (on navigation keys ⬌⬍) to leave superscript mode.