Since $e^x\sim 1+x$ as $x\to 0$ and $M^\theta=e^{\theta\log M}$, $$M^\theta\sim 1\color{red}{+}\log(M)\theta $$ as $\theta\to 0$.
– Jack D'AurizioOct 11 '16 at 23:58
1
Actually, $M^{\theta}-1 \sim \log(M)\theta$ as $\theta \to 0$, which is quite different from $M^{\theta}\sim1+ \log(M)\theta$.
– DidOct 12 '16 at 00:03