Let $f(x,y)=-e^{sin(5x)+cos(2y)}.$ Calculate gradf.

gradf$(x,y)=($:$,$:$)$

What $is$ the directional derivative $ofz=f(x,y)=-e^{sin(5x)+cos(2y)}in$ the direction $of$ the vector vec$(v)=-i-3j?$ Put your formula into either exact form, $or$ round all numerical values $toat$ least $3$ decimal places.

$f_{\text{v}\text{e}\text{c}(v)}(x,y)=$

What $is$ the directional derivative $ofz=f(x,y)=-e^{sin(5x)+cos(2y)}at$ the point $(3,-1)in$ the direction $of$ the vector vec$(v)=-i-3j?$ Round your answer $toat$ least $3$ decimal places.

$f_{\text{v}\text{e}\text{c}(v)}(3,-1)=$