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Solution 3.3:5e
From Förberedande kurs i matematik 1
The argument of ln can be written as
and with the logarithm law,
\displaystyle \ln \frac{1}{e^{2}}=\ln e^{-2}=\left( -2 \right)\centerdot \ln e=\left( -2 \right)\centerdot 1=-2