math T help..urgent n thanks...

[ken_cck_kid]

given f(x)= log2 x (x=R+).........(log x with base two)
g(x)= 1/x (x=R+)

does g(f(X)) exist? pls let me know why..thanks..

[lawteoh]

given f(x)= log2 x (x=R+).........(log x with base two)
g(x)= 1/x (x=R+)

does g(f(X)) exist? pls let me know why..thanks..

For your information, for g[f(x)] to exist, the range of f must be included in domain g.

from here, the range of f(x) is all real numbers. But the domain of g is only positive real numbers. So definitely g[f(x)] do not exist. that's all lor..