Question

The directional derivative of Φ(x,y,z) = x2yz+4xz2 at (1, -2, 1) in the direction of $2\hat{i}-\hat{j}-2\hat{k}$ is

• A. $-\frac{1}{3}$
• B. $\frac{2}{3}$
• C. $-\frac{13}{3}$
• D. $\frac{13}{3}$

Answer 1

Answer: (C)

$-\frac{13}{3}$

Answer 2

The correct option is(C):$-\frac{13}{3}$.