[tex]log\ a=2\\\\log\ \frac1{\sqrt{a}}=log\ (1\ :\ \sqrt{a})=log\ 1-log\sqrt{a}=\\\\=0-1=-1\\\\\\\\log\ 1=x\\\\log_{10}\ 1=x\\\\10^x=1\\\\x=0\\\\log\ \sqrt{a}=log_{10}\ a^{\frac12}=\frac12log\ a=\frac12\cdot2=1[/tex]