Solution:
(i)
f(x)=11–cosx\mathrm{f}(\mathrm{x})=\frac{1}{\sqrt{1-\cos \mathrm{x}}}
As per the question,
It is known that the value of
Multiply by negative sign, we have
Or
When we add 1, we have
So now,
Or,
As a result, the domain of
(ii)
As per the question,
For real value of
When
When
Therefore,
As a result, the domain of