Show that the plane 3x+12y-6z-17 touches the conicoid 3x^2-6y^2+17=0.Find also the point of contact.Please help me solve this problem...

Question

anonymous · Answer

Sorry,the conicoid should have been 3x^2-6y^2+9z^2+17=0

amistre64 · Answer

if it says the "point" of contact, that might suggest that the tip of the cone is it

amistre64 · Answer

is that "conicoid" a hyperbolic cylindar?

anonymous · Answer

It may be anything,actually we have to solve it using partial derivatives,but I don't know how...

amistre64 · Answer

partials suggest gradients

amistre64 · Answer

the gradient of a plane is its normal vector

partials take derivatives like usual, but consider the other variables as constants

amistre64 · Answer

F = 3x^2-6y^2+17

Fx = 6x
Fy = -12y
Fz = 0

the gradient at any point is therefore defined as:

(6x, -12y, 0)

amistre64 · Answer

make sure your posted information is accurate