16.06.02 Find a vector function ry.")for the surface. a. The plane that passes through the point (1,2,-3) and is parallel to the vectors (1,1,-1) and (1,-1,1). b. The lower half of the ellipsoid 2x +4y +2 =1 c. The part of the sphere of radius 4 centered at the origin that lies between the planes z =-2 and z = 2