请问上一步怎么变成的1-cosx/sinx?过程谢谢 化简(1/sinx+1/tanx)(1-cosx)=? 请给...
\u4e3a\u4ec0\u4e48tanx/2=1-cosx/sinx=sinx/1+cosx\uff1f\u8c22\u8c22\u5176\u5b9e\u4e0a\u5b66\u7684\u65f6\u5019\u6211\u4e5f\u4e0d\u61c2\u4e3a\u4ec0\u4e48\u6709\u4e9b\u5f88\u7b80\u5355\u7684\u4e1c\u897f\uff0c\u975e\u5f97\u8981\u5199\u51fa\u8bc1\u660e\u6b65\u9aa4\uff01\u2026\u81f3\u4e8e\u8fd9\u9053\u9898\u6211\u6559\u4f60\u65b9\u6cd5\u5427\u3002\u5148\u753b\u4e2a\u4e09\u89d2\u5f62\uff0c\u89d2\u5ea6\u968f\u4f60\u5b9a\uff0c\u6700\u597d\u76f4\u89d2\u7684\uff0c\u968f\u4fbf\u4ee3\u5165\u89d2\u5ea6\u5c31\u53ef\u4ee5\u4e86
=(1/sinx+cosx/sinx)(1-cosx)
=(1+cosx)(1-cosx)/sinx
=[1-(cosx)\u7684\u5e73\u65b9]/sinx
=(sinx)\u7684\u5e73\u65b9/sinx
=sinx
1-2sin²（x/2）=cosx
所以2sin²（x/2）=1-cosx
2[sin(x/2)]^2 = 1- cosx
2sin(x/2).cos(x/2) = sinx
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绛旓細1-COSA=2(sinA/2)^2 sinA=2sinA/2 cosA/2 鎵浠,宸﹁竟=sinA/2 / cosA/2=tanA/2 鍙宠竟鍚岀悊寰楀埌.
绛旓細鐢ㄨ緟鍔╄鍏紡锛氬師寮=(1/2)[(鈭3/2)sin2x + (3/2)cos2x]=(1/2)•鈭歔(鈭3/2)² + (3/2)²]•sin(2x + 蠁)鍏朵腑tan蠁=(3/2)/(鈭3/2)=鈭3 =(1/2)•鈭3•sin(2x + 蟺/3)=(鈭3/2)•sin(2x + 蟺/3)
绛旓細鏈涢噰绾炽
绛旓細鍊嶈鍏紡锛屽鍥炬墍绀
