Which graph is a translation of f(x) = x2 , according the rule: y = x2 - 5  im 100% sure it is the third graph just wanted verification plus i got it right.

For this case we have the following original function:
 
 We apply the following transformation:
 Vertical displacements:
 Assume k> 0
 To graph f (x) - k, move the graph k units down.
 Applying the transformation for k = 5 we have:
 
 Therefore, the graph moves 5 units down.
 
 Third graph