What is the domain and range of f(x) = ln(x): x>0f(x)=ln(x):x>0?

1 Answer
Sep 26, 2016

(-oo,+oo)(,+)

Explanation:

f(x) = lnxf(x)=lnx is, as you state, defined for x>0x>0. Thus its domain is 0,+oo)0,+).

On the other hand, since lim_"x->0"lnx =-oo the range of lnx is (-oo,+oo)

We can get a sense of this by looking at the graph of lnx below:

graph{lnx [-1.596, 9.504, -3.33, 2.217]}