Hi there!

Can someone please explain to me the reason for,

y = In[In(sin x)]

does it exist?

and the answer cannot be

dy/dx = cot x / In (sin x) because it is apparently it is incorrect.

would the anwer be: dy/dx = In (sin x) / In (sin x)

but if it is, it does not make sense when using the formula of,

d/dx (In f(x)) = f ' (x) / f (x )

So, would the answer then be, -1 < sin x < 1

or is the answer, 0 < sin x < 1

and also with y = In[In(cos x)]

doesnotexist due to (In cos x) always being negative.

Thanks heaps if you get this, true champ!!!!!