Chọn mệnh đề đúng:

A. −3

B. \[\frac{1}{3}\]

C. \[ - \frac{1}{3}\]

D. 3

A. \[\frac{1}{5}\]

B. \[ - \frac{1}{5}\]

C. 5

D. −5

A. \[{\rm{lo}}{{\rm{g}}_{\rm{a}}}{\rm{c = lo}}{{\rm{g}}_{\rm{a}}}{\rm{b}}{\rm{.lo}}{{\rm{g}}_{\rm{b}}}{\rm{c}}\]

B. \[{\rm{lo}}{{\rm{g}}_{\rm{a}}}{\rm{c = }}\frac{{\rm{1}}}{{{\rm{lo}}{{\rm{g}}_{\rm{c}}}{\rm{a}}}}\]

C. \[{\rm{lo}}{{\rm{g}}_{\rm{a}}}{\rm{b}}{\rm{.lo}}{{\rm{g}}_{\rm{b}}}{\rm{a = 1}}\]

D. \[{\rm{lo}}{{\rm{g}}_{\rm{a}}}{\rm{c = }}\frac{{{\rm{lo}}{{\rm{g}}_{\rm{b}}}{\rm{c}}}}{{{\rm{lo}}{{\rm{g}}_{\rm{b}}}{\rm{a}}}}\]

A. \[{\rm{T}} = - \frac{2}{5}\]

B. \[{\rm{T}} = \frac{2}{5}\]

C. \[{\rm{T}} = \frac{2}{3}\]

D. \[{\rm{T}} = - \frac{2}{3}\]

A. \[{\rm{lo}}{{\rm{g}}_{{{\rm{a}}^{\rm{3}}}}}\left( {\frac{{\rm{a}}}{{\sqrt {\rm{b}} }}} \right){\rm{ = }}\frac{{\rm{1}}}{{\rm{3}}}\left( {{\rm{1 + }}\frac{{\rm{1}}}{{\rm{2}}}{\rm{lo}}{{\rm{g}}_{\rm{a}}}{\rm{b}}} \right){\rm{.}}\]

B. \[{\mathop{\rm lo}\nolimits} {{\rm{g}}_{{{\rm{a}}^{\rm{3}}}}}\left( {\frac{{\rm{a}}}{{\sqrt {\rm{b}} }}} \right) = \frac{1}{3}\left( {1 - 2{\mathop{\rm lo}\nolimits} {{\rm{g}}_{\rm{a}}}{\rm{b}}} \right).\]

C. \[{\mathop{\rm l}\nolimits} {\rm{o}}{{\rm{g}}_{{{\rm{a}}^{\rm{3}}}}}\left( {\frac{{\rm{a}}}{{\sqrt {\rm{b}} }}} \right) = \frac{1}{3}\left( {1 - \frac{1}{2}{\mathop{\rm l}\nolimits} {\rm{o}}{{\rm{g}}_{\rm{a}}}{\rm{b}}} \right).\]

D. \[{\log _{{{\rm{a}}^{\rm{3}}}}}\left( {\frac{{\rm{a}}}{{\sqrt {\rm{b}} }}} \right) = 3\left( {1 - \frac{1}{2}{\mathop{\rm lo}\nolimits} {{\rm{g}}_{\rm{a}}}{\rm{b}}} \right).\]

A. \[\frac{3}{4}\]

B. \(\frac{1}{2}\)

C. \[\frac{1}{3}\]

D. \[\frac{5}{6}\]

A. I = 3.       

B. \[{\rm{I}} = \frac{1}{3}.\]

C. \[{\rm{I}} = - \,\frac{1}{3}.\]

D. I = −3.