8sin八分之派cos八分之派 求值怎么算?求过程谢谢! 比较sin八分之五派，cos八分之五派，tan八分之五派的大...
cos\u516b\u5206\u4e4b\u6d3e\u7684\u5e73\u65b9\u7b49\u4e8e\u591a\u5c11cos²(\u03c0/8)
=1/2*[2cos²(\u03c0/8)-1]+1/2
=1/2*cos(\u03c0/4)+1/2
=\u221a2/4+1/2
cos²(\u03c0/8)-sin²(\u03c0/8)
=cos(\u03c0/4)
=\u221a2/2
\u3010\u4e2d\u5b66\u751f\u6570\u7406\u5316\u3011\u56e2\u961f\u4e3a\u60a8\u89e3\u7b54\uff01\u795d\u60a8\u5b66\u4e60\u8fdb\u6b65
\u4e0d\u660e\u767d\u53ef\u4ee5\u8ffd\u95ee\uff01
\u6ee1\u610f\u8bf7\u70b9\u51fb\u4e0b\u9762\u7684\u3010\u9009\u4e3a\u6ee1\u610f\u56de\u7b54\u3011\u6309\u94ae\uff0cO(\u2229_\u2229)O\u8c22\u8c22
180\u5ea6\u30098pai/5>90\u5ea6\uff0c\u6240\u4ee5sin\u30090\u6700\u5927
tan<0,cos<0,tan=cos/sin\uff0c0<sin<1\u6240\u4ee5cos\u3009tan
希望能帮到你。。
4×(2×sin (派/8)×cos(派/8))=4sin (派/4)=2倍的根号下2
2sinacosa=sin2a
则原式=4sinπ/4=2√≠
原式=4sin（pi/4）=2根号2
绛旓細(1)8sin(娲/48)cos(娲/48)cos(娲/24)cos(娲/12)= 4sin(娲/24)cos(娲/24)cos(娲/12)= 2sin(娲/12)cos(娲/12)=sin(娲/6锛=0.5 2)cos(娲/9)cos(2娲/9)cos(3娲/9)cos(4娲/9)= 杩欐牱鍐欏お鐑︿簡 (3))tan(娲/12)-cot(娲/12)=tan(娲/12)-1/[tan(娲/12)]={[tan...
绛旓細=1-sin(蟺/8)-sin(蟺/8) =1-2sin(蟺/8) 鑰cos锛埾/4锛=鈭2/2 鍒1-2sin(蟺/8)=鈭2/2 浜庢槸sin(蟺/8)=锛2-鈭2锛/4 鐢变簬0<蟺/8<蟺 鎵浠 sin锛埾/8锛>0 鎵浠in锛埾/8锛=鈭歔锛2-鈭2锛/4]=[鈭(2-鈭2)]/2 绠楀嚭鏉ユ槸鏍瑰彿涓嬭繕鍚湁鏍瑰彿锛屾墍浠ュ钩鏃舵病蹇呰璁＄畻鐨勩
绛旓細1.sin20掳cos70掳锛媠in10掳sin50掳 =sin20掳sin20掳锛(cos40掳-cos60掳)/2 =(1-cos40掳)/2锛(cos40掳-cos60掳)/2 =(1-cos60掳)/2 =(1-1/2)/2 =1/4.2.cos(5蟺/8+蟺/8)=cos5蟺/8cos蟺/8-sin5蟺/8sin蟺/8=-鈭2/2 cos(5蟺/8-蟺/8)=cos5蟺/8cos蟺/8+sin5...
绛旓細8sin 娲/32 cos娲/32 cos娲/16 cos娲/8 =8sin 娲/32 cos娲/32 cos娲/16 cos娲/8 =4sin娲/16 cos娲/16 cos娲/8 =2sin娲/8cos娲/8 =sin娲/4 =鏍瑰彿2/2
绛旓細1銆(1) 鏈澶у 3 鍙栨渶澶у兼椂 2x-鈭忥紡4=2n鈭 x=n鈭忥紜鈭忥紡8 (n=0銆1銆2...)澶夯鐑︿簡 鍐欎笉涓嬪幓浜嗭紒锛
绛旓細姝ｅ鸡锛sin锛夌瓑浜庡杈规瘮鏂滆竟锛泂inA=a/c 浣欏鸡锛cos锛夌瓑浜庨偦杈规瘮鏂滆竟锛沜osA=b/c 姝ｅ垏锛坱an锛夌瓑浜庡杈规瘮閭昏竟锛泃anA=a/b 浣欏垏锛坈ot锛夌瓑浜庨偦杈规瘮瀵硅竟锛沜otA=b/a 浜屻侀攼瑙掍笁瑙掑嚱鏁板叕寮 鍏充簬鍒濅腑涓夎鍑芥暟鍏紡锛屽湪鑰冭瘯涓敤鐨勬渶澶氱殑灏辨槸鐗规畩涓夎搴︽暟鐨勭壒娈婂笺傚锛歴in30掳=1/2 sin45掳=鈭2/2 sin60...
绛旓細sin(蟺/8)=sin(180掳/8)=sin锛45掳/2锛=卤鈭氥愶紙1-cos45掳锛/2銆=卤鈭氥愶紙2-鈭2锛/4銆=卤銆愨垰锛2-鈭2锛夈/2
绛旓細鍘熷紡=2sin(蟺/9)cos(蟺/9)cos(2蟺/9)cos(4蟺/9)/2sin(蟺/9)=sin(2蟺/9)cos(2蟺/9)cos(4蟺/9)/2sin(蟺/9)=2sin(2蟺/9)cos(2蟺/9)cos(4蟺/9)/4sin(蟺/9)=sin(4蟺/9)cos(4蟺/9)/4sin(蟺/9)=sin(8蟺/9)/8sin(蟺/9)=sin(蟺-8蟺/9)/8sin(蟺/9)=sin...
绛旓細4銆佸師寮=2sin(7鍒嗕箣2蟺)cos(7鍒嗕箣2蟺)cos(7鍒嗕箣4蟺)cos(7鍒嗕箣8蟺)/[2sin(7鍒嗕箣2蟺)]=2sin(7鍒嗕箣4蟺)cos(7鍒嗕箣4蟺)cos(7鍒嗕箣8蟺)/[4sin(7鍒嗕箣2蟺)]=2sin(7鍒嗕箣8蟺)cos(7鍒嗕箣8蟺)/[8sin(7鍒嗕箣2蟺)]=sin(7鍒嗕箣16蟺)/[8sin(7鍒嗕箣2蟺)]=sin(7鍒嗕箣2蟺)/[8...
绛旓細銆愬弬鑰冪瓟妗堛戝浜巠=sin(2x- 蟺/4)鐨勫浘鍍忥紝鍙互锛氬厛鍋氬嚭鍑芥暟y=sinx鐨勫浘鍍忥紱鍐嶅皢y=sinx鍥惧儚妯潗鏍囩缉灏忎负鍘熸潵鐨勪竴鍗婏紝寰楀埌y=sin2x鍥惧儚锛涙渶鍚庯紝灏唝=sin2x鍥惧儚鍚戝彸骞崇Щ蟺/8涓崟浣嶏紝鍗冲彲寰楀埌y=2sin(2x- 蟺/4)鐨勫浘鍍忋
