Question

equation of the tangent plane to the ellipsoid with equation 2x^2+3y^2+4z^2=9, at the point (1,1,-1)

Answer 1

i don't need the actual answer, i just want to know where to start the problem

Answer 2

find the gradient of 2x^2+3y^2+4z^2=9

Answer 3

and then plug the point into that?

Answer 4

for the gradient i got <4x,6y,8z>

Answer 5

yes now you plug the point

Answer 6

and then what you have to do it dot product it with
(x-1,y-1,z+1)

Answer 7

you dot product <4,6,-8> with that?

Answer 8

yes .. and equate to 0 since they are perpendicular

Answer 9

(4,6,-8)(x-1,y-1,z+1) = 0
..