Display field only if checkbox is not empty

This is very straightforward but I can't figure it out in my own because i'm a noob. 

I have a checkbox field called [Profit-share arrangement]
If this is selected, there is a follow up question called [Profit-share arrangement appropriate]

I need to know the syntax to include in the follow-up question's formula field to only display this if the checkbox is checked. 

e.g. =IF([Profit share arrangement]=TRUE.....?

------------------------------
Jemma Dicks
------------------------------