Does Gnumeric support a function that returns the root of an expression?

[Lew Stivers <lewstivers medrosystems com>]

I have found the function to use to take an expression to a "y" power,  but I have been unable to locate the 
reverse.  I am trying to upgrade a spreadsheet to calculate the monthly interest to be compounded over a year 
based on knowing the desired annual rate of return.  My iPAD uses a Root function,  but I have been unable to 
find an equivalent in Gnumeric.

Thank you for your guidance.

Lew