(4)

Identity Requirement:

For , the argument must satisfy .

From the previous step, we found , where .

This gave and .

Domain Check (The Key Step):

If : The argument becomes . Since is undefined. This case is rejected. [1]

If : The argument becomes . Since , this case is valid. [2]

for :

We only solve .

Since , its log must be , so .

(a constant between 0 and 1). [4]

In the interval (two full cycles of cosine):

Cycle has 2 solutions.

Cycle : has 2 solutions.

Total Solutions = 4.

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