Hi everyone...

Recently I resolved a problem using this equation (stopping to the 2nd term):

$\displaystyle

\ln(1+\alpha_1 x + \alpha_2 x^2 + ...) \approx \alpha_1 x + (\alpha_2 -\frac{1}{2}\alpha_1^2) x^2 +...

$

Problem is that it's new to me and I cannot prove it!!

Would someone, please, give me direction to a web site where I can find a proof?

Or, eventually, prove it for me here?

Thanks in advance!