This one has me stumped

$\displaystyle \ln (\sqrt{(\frac{1-x^2}{x^2+1}})$

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$\displaystyle \frac{1}{2} \ln \frac{1-x^2}{x^2 +1}$

This is where im stuck I belive that im right up to this part im not sure if i should do the quotient rule or the log propertie and turn it into a subtraciton problem. I tried turning it into subtraction but i got crazy numbers