Suppose w$=$xy$+$yz$,$ where

x$=$e$^(3$t$),$y$=2+$sin$($t$)$ and z$=2+$cos$(7$t$)$

A $)$ Use the chain rule to find $$ as a function of x$,$ y$,$ z$,$ and t$.$ Do not rewrite x$,$ y$,$ and z in terms of t$,$ and do not rewrite $^(3)$ as x$.$

dw$/$dt

Note: You may want to use exp$()$ for the exponential function. Your answer should be an expression in x$,$ y$,$ z$,$ and t; e$.$g$."3$x $-4$y$"$

B $)$ Use part A to evaluate dw$/$dt when $=0.$