Answer:
The directional derivative of f at A in the direction of AD is 7.
Step-by-step explanation:
Step 1:
Directional of a function f in direction of the unit vector is denoted by ,
.
Now the given points are
,
Step 2:
The vectors are given as
AB = (10-8, 9-9),the direction is
AC=(8-8,10-9), the direction is
AC=(11-8,13-9), the direction is
Step 3:
The given directional derivative of f at A is 9,
The given directional derivative of f at A is 2,
The given directional derivative of f at A is
The directional derivative of f at A in the direction of is 7.