In the given figure, each box represents a function machine. A function machine illustrates what it does with the input.Which of the following statements is correct?
$z=2 x+3$
$z=2(x+3)$
$z=\sqrt{2 x+3}$
$z =\sqrt{2( x +3)}$
If $log_{10} (xy) = 2$, then the value of $xy$ is
The side of a square is increasing at the rate of $0.2\,cm / s$. The rate of increase of perimeter w.r.t. time is $...........\,cm / s$