- #1
seanuleh
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Homework Statement
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.
Homework 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 :(
The Attempt at a Solution
Fx = y + y^2
Fx(1,1,2) = 2
Fy = x + 2xy
Fy(1,1,2) = 3
so the normal vector would be [2, 3, -1].
Please help :(