just after i finish reading the whole thing i noticed there is a rotated version...
why is there a sigma in yours? there is no sum?
it's just comparing the term independent of x.
on the LHS the term independent of x is just (p+q)C(q)
oh woops didn't read your example right!
uh well i proved it in the exam but i guess there must be an exception.
in your example they still lie on the same line that passes through the origin but on opposite sides so the args differ by \pi