... 2Tcy a, - ay sin28 = Jm.’ ‘Os 28 = JW and sin 2( 8 + n /2) = dv, - 2? xy cos 2( 8 + n /2) = 4U.Y - Uy) (0, - cy) + 4?xy JW Rewriting Eq. (1.8) as U. an =%(l+cos20) +-~ (1 ... Eq. (1.8) as U. an =%(l+cos20) +-~ (1 -cos28)+rx,sin28 ahd substituting for (sin28, cos 28 } and {sin2(8 + 7r /2) , cos 2( 8 + n /2) } in turn gives 2 2 (1.11) 0.Y + 0.v 01 = ~ and ... becomes (CE )2( 1 + 2~ y) = (CF)’(1 + 2~ n) + (FE )2( 1 + 2~ ,+, /2) - 2( CF)(FE)y From Fig. l.l3(a), (CE )2 = (CF )2 + (FE )2 and the above equation simplifies to 2( CE )2~ ,, = ~(CF)’E,...