By about how much will

$($x$,$ y$,$ z$)=$ln$2$x

$2$

$+$y

$2$

$+$z

$2$

change if the point P$($x$,$ y$,$ z$)$ moves from P$0$

$(3,4,12)$ a distance of

ds$=0\mathrm{.}1$ unit in the direction of $3$i $+6$j $-2$k