Solution

ID: past-exam-of-the-mathematical-methods-ii-course-of-the-university-of-oxford/2016/2/b/solution

For the real-valued expression, first consider the one-sided limit . Its natural logarithm is . Since ,
using . The continuity of the exponential function therefore gives right-hand limit .
The printed two-sided notation needs qualification: for , so raising it to an arbitrary real power does not define a real-valued function throughout a left neighbourhood of zero. There is consequently no ordinary two-sided real limit on an open punctured neighbourhood with the expression as written. The value is the natural right-hand interpretation.

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