dx,dy的展开: dx=cOsB团=/、B32.BB +…)ldl 2!4!6! 6 +..ad 2-2A2242A27202A 7418 8A4384A8720×6412+…) dy=sin B dl=B β3β3β +.)ll 3!5!7 2A2b22)× 1202A250402A 4 2A248443840405040×12844+…l 跳转到第一页跳转到第一页 dx，dy的展开： dx = cosβ dl )dl 2! 4! 6! (1 2 4 6 +  −  +  = − dl A l A l A l ) ] 2 ( 720 1 ) 2 ( 24 1 ) 2 ( 2 1 [1- 6 2 2 4 2 2 2 2 2 = + − + dl A l A l A l ) 8 384 720 64 (1 1 2 1 2 8 8 4 4 +  = − + − dy β dl (β )dl 3! 5! 7! sin 3 5 7 +  −  +  =  = − dl A l A l A l A l ) ] 2 ( 5040 1 ) 2 ( 120 1 ) 2 ( 6 1 - 2 [ 7 2 2 5 2 2 3 2 2 2 2 = + − + dl A l A l A l A l ) 2 48 3840 5040 128 ( 1 4 1 4 1 0 1 0 4 6 2 2 +  = − + −