4 hours because noon is 12. 8-12 is 4

has gradient

which at the point (-1, 4, 3) has a value of

I'm not sure what the given direction vector is supposed to be, but my best guess is that it's intended to say
, in which case we have

Then the derivative of
at (-1, 4, 3) in the direction of
is

I don’t even know how to get the information from the school that is not working on my
2+2 is 4 - 1 that’s three quick maths ok sorry bye have a good day