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

Find the unit vector with positive z component which is normal to the surface z=xy+xy^2 at the point (1,1,2) on the surface.

2. Relevant equations

Well no real relevant equations i guess... but the thing is i know how to get the normal vector, i know how to convert it to a unit vector i just have no idea how to make the z-component positive. A friend suggested that i just change the z-component to 1 in the solution however i am convinced that this is an entirely different vector and is more than likely NOT the solution. Please help :(

3. The attempt at a solution

F_{x}= y + y^2

F_{x}(1,1,2) = 2

F_{y}= x + 2xy

F_{y}(1,1,2) = 3

so the normal vector would be [2, 3, -1].

Please help :(

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# Homework Help: Normal Vectors to a Surface

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