Question

f(x,y) = x^2+xy^2+1

1) Find normal vector to f(x,y)=3 given the points (2,1)
?

Answer 1

The normal vector is given by:\[N=\left(\begin{matrix}f_x(x_0,y_0) \\ f_y(x_0,y_0) \\ -1\end{matrix}\right)\]

Answer 2

So, @Amum do you know how to find the partial derivatives?

Answer 3

yh i do

Answer 4

Good, then just find those and insert your point :) That should give you the normal vector

Answer 5

Got it, thx