I'm having trouble working out the tangent plane of an equation at a specified point (4,1,-2) The equation being [tex]9x^2 - 4y^2 - 25z^2 = 40[/tex] now [tex]\nabla f = (18x, -8y, -50z)[/tex] yeh? Just reading off this should give us the normal vector shouldn't it? (18,-8,-50) and from that we can work out the equation of the plane. 18(x-4) - 8(y-1) -50(z-(-2)) = 0 Is this corrent or am I using a horribly flawed method?
Think I've worked it out for myself. Method was sorta wrong. Once I have Grad F, all I need to do is sub in the values of the point and It will give me the normal vector and from that I can work out the equation. I think thats right.