1. Find the unit vector normal to the plane 4x - 5y + 3z = 60. Then find the distance from the origin to the plane.
2. Write the expression for the differential length vector d l at the point (1, 2, 8) on the straight line y = 2x, z = 4y, and having the projection dx on the x-axis.
3. Write the expression for the differential length vector d l at the point (4, 4, 2) on the curve x = y = z2 and having the projection dz on the z-axis.