Answer
ln$\sqrt ab=\frac{1}{2}(lna+lnb)$
Work Step by Step
Use logarithmic properties $ln(pq) = lnp+lnq$ and $ln(p)^{m}= m lnp$
Consider the quantity $ln\sqrt ab$ as follows:
ln$\sqrt ab=ln(ab)^{\frac{1}{2}}$
This implies
ln$\sqrt ab=\frac{1}{2}ln(ab)$
Hence, ln$\sqrt ab=\frac{1}{2}(lna+lnb)$
