（1-cosx）/sinx=tan什么
\u8bf7\u95ee\u4e3a\u4ec0\u4e48(1-sinx)/cosx = tan(x/2)?\u9519\u4e86\u3002
(1 -sinx)/cosx = [ 1 -tan (x/2) ] / [ 1 +tan (x/2) ].
\u5e94\u8be5\u662f\uff1a
(1 -cos x) /sin x = tan (x/2),
\u6216\uff1a
sin x /(1 +cos x) = tan (x/2).
= = = = = = = = =
1. (1 -cos x) /sin x = tan (x/2).
\u8bc1\u660e\uff1a\u56e0\u4e3a cos x =1 -2 [ sin (x/2) ]^2,
sin x = 2 sin (x/2) cos (x/2),
\u6240\u4ee5 (1 -cos x) /sin x = 2 [ sin (x/2) ]^2 / [ 2 sin (x/2) cos (x/2) ]
= sin (x/2) / [ cos (x/2) ]
= tan (x/2).
= = = = = = = = =
2. sin x /(1 +cos x) = tan (x/2).
\u8bc1\u660e\uff1a\u56e0\u4e3a sin x = 2 sin (x/2) cos (x/2),
cos x = 2 [ cos (x/2) ]^2 -1,
\u6240\u4ee5 sin x /(1 +cos x) = ... =tan (x/2).
= = = = = = = = =
\u540c\u7406,
(1 +cos x) /sin x =sin x /(1 -cos x) = cot (x/2).
cos x = [ cos (x/2) ]^2 -[ sin (x/2) ]^2
= 1 -2 [ sin (x/2) ]^2
= 2 [ cos (x/2) ]^2 -1,
\u516c\u5f0f\u7684\u9009\u53d6\u5f88\u5173\u952e.
\u8bc1\u660e\uff1a\u628a\u5206\u5b50\u62c6\u5f00\uff0c\u5316\u7b80\uff0c\u518d\u7528\u500d\u89d2\u516c\u5f0f\u5373\u53ef \u539f\u5f0f\uff1dsinx/(1+cosx)+(1+cosx)/(1+cosx) \uff1d1+sinx/(1+cosx) \uff1d1+2sin\uff08x/2\uff09cos\uff08x/2\uff09/2cos^2\uff08x/2\uff09 \uff1d1+sin\uff08x/2\uff09/cos\uff08x/2\uff09 \uff1d1+tan\uff08x/2\uff09 \u547d\u9898\u5f97\u8bc1
(1-cosx)/sinx =sinx(1-cosx)/sinx =sinx(1-cosx)/(1-cosx) =sinx(1-cosx)/(1+cosx)(1-cosx) =sinx/(1+cosx) =2sin(x/2)cos(x/2)/2cos(x/2) =sin(x/2)/cos(x/2) =tan(x/2)绛旓細涓嶈兘鐢ㄦ媺鏍兼湕鏃ヤ腑鍊煎畾鐞嗐傝繖棰樹笉鑳界敤鎷夋牸鏈楁棩涓煎畾鐞,鍥犱负鎷嗘垚[cos(sinx)-cosx]/(sinx-x)*(sinx-x)/(1-cosx)sinx涔嬪緦,鍒嗗埆璁＄畻姣忛」鏋侀檺.绗竴椤圭敤鎷夋牸鏈楁棩涓煎畾鐞嗗緱鏋侀檺鏄0,鑰岀浜岄」鐢ㄧ瓑浠锋棤绌峰皬鏇挎崲寰楁瀬闄愭槸鈭,鎵浠ヤ笉鑳藉埄鐢ㄧН鐨勬瀬闄愮瓑鏂兼瀬闄愮殑绉潵鎷嗗紑.
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