Consider the planes 2x + 1y + 5z = 1 and 2x + 5z = 0.

(A) Find the unique point P on the y-axis which is on both planes. ( ? , ? , ? )

(B) Find a unit vector u with positive first coordinate that is parallel to both planes.
? I + ? J + ? K

(C) Use the vectors found in parts (A) and (B) to find a vector equation for the line of intersection of the two planes,r(t) =
? I + ? J + ? K

Respuesta :

B is easy, given 2x + 1y + 5z = 1 and 2x + 5z = 0, normal vectors of those planes are (2,1,5) and (2,0,5), cross product will give the parallel vector, divide by its length so it gives the unit vector