I think you're right:

 =

 =



Rationalize the denominator.

The denominator needs 2 more factors
of 2 to become a perfect cube, so
we multiply the fraction under the
radical by 2*2.  But if you
multiply the denominator by 2*2
you must multiply the numerator by
2*2 also.



The 2*2*2 on the bottom can be
written as 2³, and the 2*2 in the
top can be written as 4



Take cube roots of top and bottom



Take individual cube roots of -1 and 4
in the top and taking the cube root of 
the bottom jsut gives 2



The cube root of -1 is just -1

 

or just



Yes, you're right.

Edwin