sin2π-x=x吗？ sin(2π+x)=？
sin(x+\u03c0/2)\u548csin(x-\u03c0/2)\u7684\u533a\u522b?\u600e\u4e48\u5224\u65ad\u5b83\u4eec\u7684\u6b63\u8d1f\u5462\uff1fsin(x-\u03c0/2)
=-sin(\u03c0/2-x)
=-cosxsin(x+\u03c0/2)=cosx\u4e00\u822c\u60c5\u51b5\u4e0b\u4e8c\u8005\u4e0d\u7b49\u3002
\u53ea\u6709\u5f53x=k\u03c0+\u03c0/2\u65f6\u76f8\u7b49\u3002
\u540c\u89d2\u4e09\u89d2\u51fd\u6570\u57fa\u672c\u5173\u7cfb\u5f0f\u4ecb\u7ecd
1\u3001\u5012\u6570\u5173\u7cfb\uff1atan\u03b1 \u00b7cot\u03b1=1\u3001sin\u03b1 \u00b7csc\u03b1=1\u3001cos\u03b1 \u00b7sec\u03b1=1\uff1b
2\u3001\u5546\u7684\u5173\u7cfb\uff1a sin\u03b1/cos\u03b1=tan\u03b1=sec\u03b1/csc\u03b1\u3001cos\u03b1/sin\u03b1=cot\u03b1=csc\u03b1/sec\u03b1\uff1b
3\u3001\u548c\u7684\u5173\u7cfb\uff1asin²\u03b1+cos²\u03b1=1\u30011+tan²\u03b1=sec²\u03b1\u30011+cot²\u03b1=csc²\u03b1\u3002
\u7b49\u4e8esinx\uff0c\u662f\u4e2a\u4ee52\u03c0\u4e3a\u5468\u671f\u7684\u5468\u671f\u51fd\u6570
解：sin2π-x ≠ xsin2π-x=0-x
=-x
sin2∏=0
sin2∏－x=-x
sin（2π-x）=sin（-x）=-sinx
绛旓細sin2蟺-x=0-x =-x
绛旓細sin蟺x涓嶇瓑浜sinx锛屼袱鑰呬箣闂存病鏈変换浣曞叧绯汇倅=sin蟺x鏄懆鏈熶负2鐨勬寮﹀嚱鏁帮紝y=sinx鏄懆鏈熶负2蟺鐨勬寮﹀嚱鏁帮紝鍥惧儚涓嶄竴鏍凤紝鐩稿悓鐨勮嚜鍙橀噺瀵瑰簲鐨勫嚱鏁板间篃涓嶇浉鍚屻俿in锛埾-x锛=sinx锛宻in锛埾+x锛=-sinx銆俿in锛2蟺+x锛=sinx锛宻in锛2蟺-x锛=-sinx銆sin蟺x鑳藉寲鎴恠in(蟺x)=sin(蟺-蟺x)鈮埾-蟺x=...
绛旓細sin(蟺/2+x)=cosx cos(蟺/2+x)=-sinx sin(蟺-x)=sinx cos(蟺-x)=-cosx sin(蟺/2-x)=cosx cos(蟺/2-x)=sinx sin(蟺+x)=-sinx cos(蟺+x)=-cosx sin(3蟺/2+x)=-cosx cos(3蟺/2+x)=sinx sin(3蟺/2-x)=-cosx cos(3蟺/2-x)=-sinx ...
绛旓細sin(蟺-x)=2鍒嗕箣鏍瑰彿3 x鈭堛-蟺,蟺銆戝垯锛毾-x鈭堛0,2蟺銆戞墍浠,蟺-x=蟺/3鎴2蟺/3 寰楋細x=蟺/3鎴2蟺/3,7,姹傝缁嗙偣鐨勬楠,瑙:鍥犱负x鈭圼-蟺,蟺]sin(蟺-x)=sinx=鏍瑰彿3/2 x=蟺/3 鎴=2蟺/3,0,瑙ｇ敱sin(蟺-x)=2鍒嗕箣鏍瑰彿3 鍗硈inx=鈭3/2 鍙堝洜涓簒鈭堛-蟺,蟺銆戝垯x=蟺/...
绛旓細sin(蟺/2-x)=cosx sin(蟺/4-x)=鈭2/2(cosx-sinx)sin(n蟺-x)=锛-1锛塣(n-1)sinx cos(蟺/2-x)=sinx cos(蟺/4-x)=鈭2/2(cosx+sinx)cos(n蟺-x)=(-1)^ncosx tan(蟺/2-x)=cotx tan(蟺/4-x)=(1-tanx)/(1+tanx)cot(蟺/2-x)=tanx cot(蟺/4-x)=(1+tanx)/(1...
绛旓細sin2鍒嗕箣鍏x鐨勫鏁版槸2鍒嗕箣鍏涔榗os2鍒嗕箣鍏x銆傛墍浠ワ紝sin2蟺x绛変簬2鍒嗕箣鍏涔榗os2鍒嗕箣鍏x銆傛湁鐣屽嚱鏁板苟涓嶄竴瀹氭槸杩炵画鐨勩傛牴鎹畾涔夛紝?鍦―涓婃湁涓婄晫锛屽垯鎰忓懗鐫鍊煎煙?鏄竴涓湁涓婄晫鐨勬暟闆嗐傛牴鎹‘鐣屽師鐞嗭紝?鍦ㄥ畾涔夊煙涓婃湁涓婄‘鐣屻備竴涓壒渚嬫槸鏈夌晫鏁板垪锛屽叾涓X鏄墍鏈夎嚜鐒舵暟鎵缁勬垚鐨勯泦鍚圢銆傜敱?=sinx鎵瀹氫箟鐨...
绛旓細cos鍜宻in涔嬮棿鐨勮浆鎹㈠叕寮忔槸cos(x)=sin(蟺/2-x)銆1.浠嬬粛cosine鍜宻ine鐨勫畾涔夛細cosine锛堜綑寮︼級鍜宻ine锛堟寮︼級鏄笁瑙掑嚱鏁颁腑鐨勪袱涓噸瑕佸嚱鏁帮紝瀹冧滑涓庡崟浣嶅渾涓婄殑鐐圭殑鍧愭爣鏈夊叧銆傚湪涓涓互鍘熺偣涓轰腑蹇冦佸崐寰勪负1鐨勫崟浣嶅渾涓婏紝瀵逛簬浠绘剰涓涓搴锛堝姬搴﹀埗锛夛紝鐐筆(x,y)鐨勬í鍧愭爣灏辨槸cos(x)锛岀旱鍧愭爣灏辨槸sin(x...
绛旓細浣犲ソ锛屽懆鏈熷彲浠ヤ负璐熸暟锛屽洜涓哄湪璇sinx鐨勫懆鏈熶负2蟺鏃讹紝姝ｇ‘鐨勮〃杩版槸鏈灏忔鍛ㄦ湡锛屾墍浠ュ懆鏈熺悊璁轰笂鍙互涓鸿礋鏁帮紝浣嗘槸瀹為檯鎴戜滑涓嶈繖涔堣銆俿in锛-x锛夌殑鍥惧儚涓嶆槸杩欎箞骞崇Щ锛岃屾槸sinx鍏充簬x杞存垨鑰厃杞寸殑瀵圭О鍥惧舰銆
绛旓細瀵广備笉闇瑕侀氳繃鍥惧儚鍙樻崲寰楀埌鍛锛屼袱鑰呭浘鍍忕浉鍚屻
绛旓細浣犵敾鍑SINX鐨勫浘鍍忓氨鐭ラ亾浜 鎴戝厛缁欎綘鍑犱釜鍏紡鈥旇瀵煎叕寮忥紝浼拌浣犱篃涓嶅お鐞嗚В sin(蟺-x)=sinx sin(2蟺+x锛=sinx sin(蟺/2+x)=cosx sin(蟺/2-x)=cosx
