Practice problem
Find the directional derivative Duf(x,y)D_uf(x,y)Duf(x,y) if f(x,y)=2x3−5xy+3y2f(x,y)=2x^3-5xy+3y^2f(x,y)=2x3−5xy+3y2 and u\bf{u}u is the unit vector given by the angle θ=π3\theta=\frac{\pi}{3}θ=3π. What is Duf(2,3)D_uf(2,3)Duf(2,3)?
112+53\frac{11}2+5\sqrt3211+53
92+43\frac92+4\sqrt329+43
5+335+3\sqrt35+33
72+63\frac72+6\sqrt327+63
Type a concept, like “slope” or “photosynthesis”.
