Practice problem
Find the directional derivative Duf(x,y)D_uf(x,y)Duf(x,y) if f(x,y)=2+3xyf(x,y)=2+3x\sqrt yf(x,y)=2+3xy and v=<4,−2>\textbf{v}=<4,-2>v=<4,−2>. What is Duf(4,5)D_uf(4,5)Duf(4,5)?
21.46621.46621.466
15.315.315.3
9.269.269.26
4.84.84.8
Type a concept, like “slope” or “photosynthesis”.
