\(The complex numbers u and w are defined by u = -1 + 7i and w = 3 + 4i.\)

1. Showing all your working, find in the form x + iy, where x and y are real, the complex numbers u - 2w and \(\frac{u}{w}\).
2. In an Argand diagram with origin O, the points A, B and C represent the complex numbers u, w and u - 2w respectively. Prove that angle AOB = \(\frac{1}{4}\pi\).
3. State fully the geometrical relation between the line segments OB and CA.