Let $f(x,y)=2e^{sin(3x)cos(3y)}.$ Calculate gradf.

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

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

$$

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

$f_{\text{v}\text{e}\text{c}(v)}(5,-3)=$

$$