cos180度等于多少? 如何计算cos180度
cos180\u5ea6\u30010\u5ea6\u300190\u5ea6\uff0csin180\u5ea6\u30010\u5ea6\u300190\u5ea6\u3001\u8fd8\u6709tan\u8fd9\u4e9b\u90fd\u7b49\u4e8e\u591a\u5c11\uff1f1\u3001cos180\u00b0=-1\uff1bcos0\u00b0=1\uff1bcos90\u00b0=0\u3002
2\u3001sin180\u00b0=0\uff1bsin0\u00b0=0\uff1bsin90\u00b0=1\u3002
3\u3001tan180\u00b0=0\uff1btan0\u00b0\u4e0d\u5b58\u5728\uff1btan90\u00b0=0\u3002
\u6269\u5c55\u8d44\u6599\uff1a
1\u3001COS\uff08\u4f59\u5f26\u51fd\u6570\uff09\u4e00\u822c\u6307\u4f59\u5f26\uff08\u6570\u5b66\u672f\u8bed\uff08\u4e09\u89d2\u51fd\u6570\u7684\u4e00\u79cd\uff09\uff09\u3002
2\u3001\u4f59\u5f26\uff08\u4f59\u5f26\u51fd\u6570\uff09\uff0c\u4e09\u89d2\u51fd\u6570\u7684\u4e00\u79cd\u3002\u5728Rt\u25b3ABC\uff08\u76f4\u89d2\u4e09\u89d2\u5f62\uff09\u4e2d\uff0c\u2220B=90\u00b0\uff0cAB\u662f\u2220C\u7684\u5bf9\u8fb9c\uff0cBC\u662f\u2220A\u7684\u5bf9\u8fb9a\uff0cAC\u662f\u2220B\u7684\u5bf9\u8fb9b\uff0c\u4f59\u5f26\u51fd\u6570\u5c31\u662fcosA=b/c\uff0c\u5373cosA=AC/AB\uff08\u8be5\u76f4\u89d2\u4e09\u89d2\u5f62\u4e2d\uff0c\u975e\u76f4\u89d2\u7684\u90bb\u8fb9\u6bd4\u659c\u8fb9\u4e3a\u4f59\u5f26\uff09\u3002
3\u3001tan\u89d2\u03b8\u5728\u4efb\u610f\u76f4\u89d2\u4e09\u89d2\u5f62\u4e2d\uff0c\u4e0e\u03b8\u76f8\u5bf9\u5e94\u7684\u5bf9\u8fb9\u4e0e\u90bb\u8fb9\u7684\u6bd4\u503c\u53eb\u505a\u89d2\u03b8\u7684\u6b63\u5207\u503c\u3002
cos180\u5ea6\u65f6\uff0cy\u4e3a\u8d1f\u6570\uff0c\uff5cy\uff5c=l\uff0ccos180\u5ea6=-1\u3002
\u4f59\u5f26\uff08\u4f59\u5f26\u51fd\u6570\uff09\uff0c\u4e09\u89d2\u51fd\u6570\u7684\u4e00\u79cd\u3002\u5728Rt\u25b3ABC\uff08\u76f4\u89d2\u4e09\u89d2\u5f62\uff09\u4e2d\uff0c\u2220C=90\u00b0\uff0c\u2220A\u7684\u4f59\u5f26\u662f\u5b83\u7684\u90bb\u8fb9\u6bd4\u4e09\u89d2\u5f62\u7684\u659c\u8fb9\uff0c\u5373cosA=b/c\uff0c\u4e5f\u53ef\u5199\u4e3acosa=AC/AB\u3002\u4f59\u5f26\u51fd\u6570\uff1af(x)=cosx\uff08x\u2208R\uff09\u3002
\u6269\u5c55\u8d44\u6599
\u4e8c\u500d\u89d2\u516c\u5f0f
sin2\u03b1=2sin\u03b1cos\u03b1
tan2\u03b1=2tan\u03b1/(1-tan^2(\u03b1))
cos2\u03b1=cos^2(\u03b1)-sin^2(\u03b1)=2cos^2(\u03b1)-1=1-2sin^2(\u03b1)
\u534a\u89d2\u516c\u5f0f
sin^2(\u03b1/2)=(1-cos\u03b1)/2
cos^2(\u03b1/2)=(1+cos\u03b1)/2
tan^2(\u03b1/2)=(1-cos\u03b1)/(1+cos\u03b1)
tan(\u03b1/2)=sin\u03b1/(1+cos\u03b1)=(1-cos\u03b1)/sin\u03b1
COS180=-1 你可以借助COS的曲线图去记忆的~~~
cos180度等于-1
负1,100%正确
-1 ，画出曲线图就可以看出。
绛旓細3銆乼an180掳=0锛泃an0掳涓嶅瓨鍦紱tan90掳=0銆
绛旓細cos180搴︾瓑浜-1
绛旓細cos锛180搴︼級绛変簬-1銆傚湪涓夎鍑芥暟涓紝cos锛埼革級琛ㄧず涓涓鐨勪綑寮﹀笺偽告槸浠ュ姬搴︿负鍗曚綅鐨勮搴︼紝鑰屼笉鏄互搴︽暟涓哄崟浣嶃備笉杩囷紝鍙互灏嗗害鏁拌浆鎹负寮у害鏉ヨ绠椼180搴︾瓑浜蟺寮у害锛堝姬搴︿笌搴︿箣闂寸殑杞崲鍏紡涓猴細1搴=蟺/180寮у害锛夈傚洜姝わ紝cos锛180搴︼級鍙互鍐欎负cos锛埾锛夈傛牴鎹笁瑙掑嚱鏁扮殑瀹氫箟锛屽彲浠ュ彇涓涓崟浣嶅渾...
绛旓細cos180=-1銆傚缓绔嬬洿瑙掑潗鏍囷紝鐢诲崟浣嶅渾锛180掳瑙掑湪x璐熷崐杞翠笂锛屾墍浠os180掳=-1/1=-1锛宻in180掳=0/1=0锛宼an180掳=0/(-1)=0銆俢os鍗充綑寮︼紙浣欏鸡鍑芥暟锛夛紝涓夎鍑芥暟鐨勪竴绉嶏紱瑙扐鐨勯偦杈规瘮鏂滆竟鍙仛鈭燗鐨勪綑寮︼紝璁颁綔cos鈭燗銆備綑寮﹀嚱鏁扮殑瀹氫箟鍩熸槸鏁翠釜瀹炴暟闆嗭紝鍊煎煙鏄紙-1锛1锛夈傚畠鏄懆鏈熷嚱鏁帮紝鍏舵渶灏...
绛旓細-1銆俢os鏄綑寮﹀嚱鏁扮殑缂╁啓锛岃〃绀虹洿瑙掍笁瑙掑舰涓偦杈逛笌鏂滆竟鐨勬瘮鍊笺俢os180搴﹁〃绀哄湪鐩磋涓夎褰腑锛岄偦杈逛笌鏂滆竟鐨勬瘮鍊间负180搴︽椂鐨勫笺俢os0搴=1锛宑os90搴=0锛宑os180搴=-1銆傝繖鏄洜涓鸿搴︿粠0搴﹀埌90搴﹀啀鍒180搴︼紝琛ㄧず鐨勬槸浠庢鏂瑰悜鍒板瀭鐩存柟鍚戝啀鍒板弽鏂瑰悜鐨勫彉鍖栥傚洜姝わ紝cos180搴=-1銆
绛旓細sin90掳=1锛 cos90掳=0锛 tan90掳涓嶅瓨鍦紝 cot90掳=0锛泂in135掳=鈭2/2锛 cos135掳=-鈭2/2锛 tan135掳=-1锛 cot135掳=-1锛泂in150掳=1/2锛 cos150掳=-鈭3/2锛 tan150掳=-鈭3/3锛 cot150掳=-鈭3锛泂in180掳=0锛 cos180掳=-1锛 tan180掳=0...
绛旓細cos180搴=-1
绛旓細cos180º= -1
绛旓細瑙ｏ細cos180掳锛宻in180掳锛宼an180掳鐨勫煎涓嬨俢os180掳=-1锛宻in180掳=0锛岃宼an180掳=sin180掳/cos180掳=0/(-1)=0銆
绛旓細cos30掳=鈭3/2锛沜os60掳=1/2锛沜os90掳=0锛沜os120掳=-1/2锛沜os150掳=-鈭3/2锛cos180掳=-1锛沜os210掳=-鈭3/2锛沜os240掳=-1/2锛沜os270掳=0锛沜os300掳=1/2锛沜os330掳=鈭3/2锛沜os360掳=1锛沜os0掳=1鎴栬卌os锛0掳+360掳脳n锛=1鍏朵腑n鍙互涓0銆1銆2銆3绛夋暣鏁般侰OS鍑芥暟鏄笁瑙...
