Question

the directional derivative of a=-2j-k in the direction of the vector b=-i-j is _____
a)
$\sqrt{3}$
b)3
c)2
d)
$\sqrt{2}$
​

Answer 1

For the f of Example 1, find the directional derivative of f at the point (3,2) in the direction of (2,1).

Solution: The unit vector in the direction of (2,1) isu=(2,1)√5=(2/√5,1/√5).

Since we are still at the point (3,2), equation (1) is still valid. We plug in our new u to obtainDuf(3,2)=12u1+9u2=24√5+9√5=33√5

Answer 2

Step-by-step explanation:

300×109%4×56_6==÷×_26^