gaokao 2015 Q7

gaokao · China · hunan-arts Indices and Surds Ratio and Proportion Problems
7. If real numbers $\mathrm { a } , \mathrm { b }$ satisfy $\frac { 1 } { a } + \frac { 2 } { b } = \sqrt { a b }$, then the minimum value of $ab$ is
A. $\sqrt { 2 }$
B. 2
C. $2 \sqrt { 2 }$
D. 4
7. If real numbers $\mathrm { a } , \mathrm { b }$ satisfy $\frac { 1 } { a } + \frac { 2 } { b } = \sqrt { a b }$, then the minimum value of $ab$ is\\
A. $\sqrt { 2 }$\\
B. 2\\
C. $2 \sqrt { 2 }$\\
D. 4