K here is an example question (there are 4 in total but I only need to learn how to do one then I can do the rest):

ln(cosh x)

I have to find the largest possible domain for this.

Now I was told that Hyperbolics are similar to exponentials, and Inverse Hyperbolics are similar to Natural Logarithms. Here I have Ln and a normal Hypberbolic, so I don't think this helps me much.

If I look on the graph of cosh x, I can see that the minimum range is 1 < y < infinity.
The Domain is all real values of x.

Lastly, I know that cosh x is in fact and exponential function in the form: 0.5(e^x + e^-x)

I cannot simply take ln's of both sides because there is a half blocking the way :s...

Any ideas on how to tackle this problem guys? I don't want the answer, just what I need to know and tactics to solve this problem.

Please advise

Please close, question was answered.