Solution

ID: past-exam-of-the-mathematics-course-of-the-year-1-of-the-natural-sciences-course-of-the-university-of-cambridge/2010/paper-1/14/a/ii/solution

The logarithm's argument is , with complex modulus one. The principal complex logarithm is therefore , giving
If denotes all logarithm values rather than the principal branch, they are for : the real part remains zero and the imaginary part changes by integer multiples of . The principal value is the conventional single-valued answer.

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