sin(-90°)等于多少 sin(-90°)等于多少?
sin(\u03b1-90\u00b0\uff09\u7b49\u4e8e\u4ec0\u4e48\uff1fsin\uff08a-90\u00b0\uff09\u9996\u5148\u5c06\u4e09\u89d2\u7b26\u53f7\u6539\u4e3acos\uff0c\u7b26\u53f7\u770b\u8c61\u9650\uff0c\u82e5a\u4e3a\u7b2c\u4e00\u8c61\u9650\u5219a-90\u4e3a\u7b2c\u56db\u8c61\u9650\uff0csin\u4e3a\u8d1f\uff0c\u6545sin\uff08a-90\u00b0\uff09=-cosa
\u7b2c\u4e8c\u4e2a\u95ee\u9898\uff0c\u5c062x\u770b\u6210\u4e0a\u8ff0a,\u5f97\u5230sin\uff082x+150\u00b0\uff09=-cos\uff082x+240\u00b0\uff09=cos\uff082x+60\u00b0\uff09
\u6240\u4ee5?=60\u00b0+k•360\u00b0,k\u662f\u6574\u6570
建议你把单位圆法搞懂,那就不愁三角函数值了哈···
sin(-90°)
=-sin(90°)
=-1
绛旓細sin锛-90掳锛=-sin锛90掳锛=-1 鍦ㄧ洿瑙掍笁瑙掑舰涓紝浠绘剰涓閿愯鈭燗鐨勫杈逛笌鏂滆竟鐨勬瘮鍙仛鈭燗鐨勬寮︼紝璁颁綔sinA锛堢敱鑻辫sine涓璇嶇畝鍐欏緱鏉ワ級锛屽嵆sinA=鈭燗鐨勫杈/鏂滆竟銆傚湪RT鈻矨BC涓紝濡傛灉閿愯A纭畾锛岄偅涔堣A鐨勫杈逛笌鏂滆竟鐨勬瘮渚块殢涔嬬‘瀹氾紝杩欎釜姣斿彨鍋氳A鐨勬寮︼紝璁颁綔sinA锛屽嵆sinA=瑙扐鐨勫杈/瑙扐鐨勬枩杈...
绛旓細鎵浠ワ紝sin(-90)=-1
绛旓細璐熶竴 棣栧厛sin(-x) = -sin(x) 杩欐槸鍏紡 鐒跺悗瑕佺煡閬搒in琛ㄧずy杞翠笂鐨勬暟 鎺ョ潃鐪嬪害鏁版槸90搴 姝f寚鐫Y杞存鍗婅酱 鎵浠ユ槸姝d竴銆愬鏋 鎸囩潃y璐熷崐杞村嵆270搴 灏辨槸璐熶竴銆戙愬鏋 搴︽暟鏄0鎴180 鍗虫寚鐫x杞 涓嶇姝h礋 閮芥槸sin(x) =0 鍥犱负鍦▂杞翠笂 鎸囩潃鍘熺偣 銆戞墍浠in璐90搴绛変簬璐熶竴 ...
绛旓細-1 寤鸿浣犳妸鍗曚綅鍦嗘硶鎼炴噦锛岄偅灏变笉鎰佷笁瑙掑嚱鏁板间簡鍝埪仿仿
绛旓細sin锛-x锛=-sin锛坸锛鎵浠in锛-90锛=-sin锛90锛=-1
绛旓細sin 鏄痽 鐨勫 . 鎵浠-90搴︾殑鏃跺. 鑰屼笖瑙掑害鏄粠x鐨勬鍗婅酱寮濮嬭绠楃殑. 鎵浠-90搴︾殑鏃跺. 鍒氬垰濂藉湪(0,-1) 杩欎釜鐐逛笂闈. 寤鸿浣犵敾涓涓潗鏍囪酱. 瀹规槗鐞嗚В闈炲父澶殈 甯屾湜鍙互甯埌浣爚 娆㈣繋杩介棶~
绛旓細鍦ㄧ洿瑙掑潗鏍囩郴涓敾涓涓崟浣嶅渾锛宻in瀵瑰簲鐨勬槸y鐨勫硷紝cos瀵瑰簲鐨勬槸x鐨勫 sin(-90)鍗充粠x杞存鍗婅酱(濮嬭竟)閫嗘椂閽堣浆90搴︼紝鍒氬ソ鍦▂杞存鍗婅酱锛屽搴旂殑y鐨勫兼槸1 鍚岀悊锛宻in270鍦▂杞存鍗婅酱锛寉鍊间负1 cos180鍦▁杞磋礋鍗婅酱锛屽搴攛鍊间负-1
绛旓細鍚勫肩殑鍙傛暟濡備笅琛ㄦ牸锛歵an90掳=鏃犵┓澶 锛堝洜涓簊in90掳=1 锛宑os90掳=0 锛1/0鏃犵┓澶 锛夛紱cot0掳=鏃犵┓澶т篃鏄悓鐞嗐
绛旓細褰撶劧鏄媺锛屼綘鍙互鐢ㄧ數鑴戜笂鐨勮绠楁満妫楠屼竴涓嬪晩
绛旓細sin锛a-90掳锛夐鍏堝皢涓夎绗﹀彿鏀逛负cos锛岀鍙风湅璞¢檺锛岃嫢a涓虹涓璞¢檺鍒檃-90涓虹鍥涜薄闄愶紝sin涓鸿礋锛屾晠sin锛坅-90掳锛=-cosa 绗簩涓棶棰橈紝灏2x鐪嬫垚涓婅堪a,寰楀埌sin锛2x+150掳锛=-cos锛2x+240掳锛=cos锛2x+60掳锛夋墍浠?=60掳+k•360掳,k鏄暣鏁 ...