Prove $\log(1+x) \lt x$ for $x\gt0$
my attempt:
I show $e^{x}\gt 1+x$ for $x\gt0$
since
$e^{x}=1+x+\frac{n(n-1)}{2}\frac{x^2}{n^2}+...$
so if $x\gt0$ then all terms are positive
so $e^{x}\gt 1+x$ for $x\gt0$
now given $e^{x}\gt 1+x$ for $x\gt0$, can I take $\log$ on both sides and show
$\log(1+x)\lt x$ for $x\gt0$
or do I have to prove firstly that $\exp(x)=e^x$ for $x\gt 0$ then I can take $\log$..
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