Given the image:
http://i.stack.imgur.com/EJ3ax.jpgand that $x_0 = 1, y_0=0$ and $\text{angles} \space θ_i
, i = 1, 2, 3, · · ·$ can be arbitrarily picked.
How can I derive a recurrence relationship for $x_{n+1}$ and $x_n$?
I actually know what the relationship is, however, don't know how to...