Let f(n) = (n),and g(n) = O(f(n)).Then g(n) = _______.  I thought of it this way, since f(n) is (n),then f(n) belongs to the set of functions defined by (n), ie,{n,$n^2$,$n^3$ ....}.  So g(n) will change accordingly , ie , g(n) will be of complexity O(n),O($n^2$),O($n^3$) ...etc. Is it correct to directly substitute functional values into O(f(n)) to get a sense of the complexity?
If f(n) = (n) and g(n) = O(f(n)), what do we know about g?
asymptotics;landau notation