Find the rate of change of f(x,y,z) = ln(x+yz^2)-sin(y+z)+xe^y at the point (0,1,-1) as you move toward the point (4,1,2)
you want the directional derivative here.
first, find the vector from (0,1,-1) to (4,1,2).
then find the unit vector in that direction
then use the formula:
where is the gradient vector of (at the point (0,1,-1)), is the dot product and is the unit vector i asked you to find.