is there any other ways to solve this natural logarithm: \ln {(a b)}
for example
\ln {ab}=\ln {a} \ln {b}

is there any other ways to solve this natural logarithm: \ln {(a b)}
for example
\ln {ab}=\ln {a} \ln {b}


I think the property you are looking for is: \log(ab) = \log(a) + \log(b). This applies to all logarithms, regardless of base, including natural logs. Hence \ln (ab) = \ln (a) + \ln (b).