(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Consider the function f (x,y). if you start at the point (4,5) and move to the point (5,6) . the directional derivative is 2. Starting at the point (4,5) and moving toward the point (6,6)gives a directional derivative of 3.Find grad f at the point (4,5) .

2. Relevant equations

3. The attempt at a solution

I don't really know how to go about this question. All I can do so far is find the unit vector.

PQ = (5-4) i + (6-5) j = i+j ; u = 1/sqrt 2 i + 1/sqrt 2 j

PR = (6-4 i +( 6-5) j = 2i+j ; u = 2/sqrt 5 i + 1/sqrt 5 j

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# Homework Help: Gradient math problem help

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