Given: $f(x,y)=x^2{y}^3-4y.$ Find $D_{u}f(x,y)in$ the direction $($:$2,5$:$)at$ the point $(2,-1,0).$

Given: $f(x,y)=4x^3{y}^2.$

$a{D}_{\frac{?}{\text{b}\text{a}\text{r}}(u)}f(x,y)in$ the direction vec$(v)=4$vec$()-3$vec$()at$ the point $(2,1,32).$

bvec$(grad)f(x,y)at$ the point $(2,1,32).$

$c(2,1,32).$