Are you sure you don't have a CTLG button? It's right above the DEL button.
Anyway, if there is no built in version you can do it by using the ^ button
just use x^(1/3)
where x is the number you want the cube root of.
In the IRC chat you said this:
so, I can't use shift to get a cubic or whatever root, as I have to hit shift to just get a normal root
Are you sure that it's a normal root? The variable root function usually has a small symbol just before the root symbol
Something like this: *√
To find the cubic root of a number (which we'll call x) do this:
Edited by Viliami, 06 December 2015 - 10:49 AM.