sinx(sinx-cosx)的化简 sinx（sinx＋cosx）怎么化简
cosx-sinx\u600e\u4e48\u5316\u7b80\uff1f sinx-cosx\u600e\u4e48\u5316\u7b80\uff1f\u89e3\u9898\u6b65\u9aa4\u5982\u4e0b
cosx-sinx
=\u221a(cosxcos45\u00b0-sinxsin45\u00b0)
=\u221acos(x+45\u00b0)
sinx-cosx
=\u221a(sinxcos45\u00b0-cosxsin45\u00b0)
=\u221asin(x-45\u00b0)
\u6269\u5c55\u8d44\u6599
\u4e09\u89d2\u51fd\u6570\u662f\u57fa\u672c\u521d\u7b49\u51fd\u6570\u4e4b\u4e00\uff0c\u662f\u4ee5\u89d2\u5ea6\uff08\u6570\u5b66\u4e0a\u6700\u5e38\u7528\u5f27\u5ea6\u5236\uff0c\u4e0b\u540c\uff09\u4e3a\u81ea\u53d8\u91cf\uff0c\u89d2\u5ea6\u5bf9\u5e94\u4efb\u610f\u89d2\u7ec8\u8fb9\u4e0e\u5355\u4f4d\u5706\u4ea4\u70b9\u5750\u6807\u6216\u5176\u6bd4\u503c\u4e3a\u56e0\u53d8\u91cf\u7684\u51fd\u6570\u3002
\u5e38\u89c1\u7684\u4e09\u89d2\u51fd\u6570\u5305\u62ec\u6b63\u5f26\u51fd\u6570\u3001\u4f59\u5f26\u51fd\u6570\u548c\u6b63\u5207\u51fd\u6570\u3002\u5728\u822a\u6d77\u5b66\u3001\u6d4b\u7ed8\u5b66\u3001\u5de5\u7a0b\u5b66\u7b49\u5176\u4ed6\u5b66\u79d1\u4e2d\uff0c\u8fd8\u4f1a\u7528\u5230\u5982\u4f59\u5207\u51fd\u6570\u3001\u6b63\u5272\u51fd\u6570\u3001\u4f59\u5272\u51fd\u6570\u3001\u6b63\u77e2\u51fd\u6570\u3001\u4f59\u77e2\u51fd\u6570\u3001\u534a\u6b63\u77e2\u51fd\u6570\u3001\u534a\u4f59\u77e2\u51fd\u6570\u7b49\u5176\u4ed6\u7684\u4e09\u89d2\u51fd\u6570\u3002\u4e0d\u540c\u7684\u4e09\u89d2\u51fd\u6570\u4e4b\u95f4\u7684\u5173\u7cfb\u53ef\u4ee5\u901a\u8fc7\u51e0\u4f55\u76f4\u89c2\u6216\u8005\u8ba1\u7b97\u5f97\u51fa\uff0c\u79f0\u4e3a\u4e09\u89d2\u6052\u7b49\u5f0f
\u53c2\u8003\u8d44\u6599\u6765\u6e90
\u767e\u5ea6\u767e\u79d1-\u4e09\u89d2\u51fd\u6570\u516c\u5f0f
sinx(sinx+cosx)
=sin²x+sin(2x)/2
=1/2-cos(2x)/2+sin(2x)/2
=1/2-\u221a2[sin45\u00b0cos2x-cos45\u00b0sin2x]/2
=1/2-\u221a2sin(45\u00b0-2x)/2
=1/2(2sin平方x-2sinxcosx)
=1/2(1-cos2x-sin2x)
=1/2-根2/2sin(2x+45度)
绛旓細f(x)=(sinx)^2+sinxcosx =[1-cos(2x)]/2+(1/2)sin(2x)=[sin(2x)-cos(2x)]/2+1/2 =[sin(2x-pi/4)*鏍瑰彿(2)]/2+1/2 鑰宻in(2x-pi/4)鐨勬渶灏忓间负-1锛屾渶澶у间负1锛屼唬鍏ュ緱鍒 f(x)鐨勬渶灏忓间负锛1-鏍瑰彿(2))/2锛屾渶澶у间负锛1+鏍瑰彿(2))/2 ...
绛旓細y锛sinx(sinx+cosx)锛漵in²x+sinxcosx 锛1/2-1/2*cos2x+1/2sin2x 锛1/2+1/2(sin2x-cos2x锛夛紳1/2+鈭2/2sin(2x-蟺锛4)鈭-1鈮in(2x-蟺锛4)鈮1 鈭村綋sin(2x-蟺锛4)=1鏃跺彇寰梱鏈澶у间负锛1/2+鈭2/2
绛旓細= ( sinx - cosx) |cosx| = ( sinx - cosx)cosx = sinx.cosx - (cosx)^2 = (1/2)sin2x - (1/2)(1+ cos2x)=(鈭2/2)sin(2x-蟺/4) - 1/2 max f(x) = f(3蟺/8) = 鈭2/2 - 1/2 case 2: 蟺/2<x<3蟺/2 f(x)= (sinx - cosx) |cosx| =(sinx - cosx)...
绛旓細瑙ｏ細y=f(x)=锛坰inx+cosx锛锛坰inx-cosx锛=sin²x-cos²x=-cos2x 锛1锛塮(-x)=-cos2(-x)=-cos2x 鈭礷(-x)=f(x)鈭磞=锛坰inx+cosx锛夛紙sinx-cosx鏄伓鍑芥暟 锛2锛夆埖y=cosx鍦╗2k蟺 锛 2k蟺+蟺]涓婃槸鍗曡皟閫掑噺锛屽湪[2k蟺+蟺 锛 2k蟺+2蟺]鏄崟璋冮掑 鈭磞=cos2x鍦╗k蟺 ...
绛旓細鍏蜂綋鍥炵瓟濡傚浘锛氳繛缁嚱鏁帮紝涓瀹氬瓨鍦ㄥ畾绉垎鍜屼笉瀹氱Н鍒嗭紱鑻ュ湪鏈夐檺鍖洪棿[a,b]涓婂彧鏈夋湁闄愪釜闂存柇鐐逛笖鍑芥暟鏈夌晫锛屽垯瀹氱Н鍒嗗瓨鍦紱鑻ユ湁璺宠穬銆佸彲鍘汇佹棤绌烽棿鏂偣锛屽垯鍘熷嚱鏁颁竴瀹氫笉瀛樺湪锛屽嵆涓嶅畾绉垎涓瀹氫笉瀛樺湪銆
绛旓細(cosx-sinx)²鐨勫師鍑芥暟? 璺眰澶х瑙ｇ瓟... 璺眰澶х瑙ｇ瓟 灞曞紑 鎴戞潵绛 1涓洖绛 #鐑# 姝﹀ぇ闈栧湪鍐ゥ鐨勮〃鐜,鎬庝箞璇勪环鏈鎭板綋?fnxnmn 2015-01-15 路 TA鑾峰緱瓒呰繃5.8涓囦釜璧 鐭ラ亾澶ф湁鍙负绛斾富 鍥炵瓟閲:1.1涓 閲囩撼鐜:14% 甯姪鐨勪汉:1浜 鎴戜篃鍘荤瓟棰樿闂釜浜洪〉 鍏虫敞 灞曞紑鍏ㄩ儴 鏈洖绛旇鎻愰棶...
绛旓細y=sinx(sinx+cosx)=sinxsinx+2sinxcosx =-1/2锛1-2sinxsinx-1+sin2x)=-1/2(cos2x+sin2x-1)=-鈭2/2锛堬紙鈭2锛/2 *cos2x+锛堚垰2锛/2 *sin2x)+1 =-鈭2/2 sin(2x+蟺/4)+1
绛旓細鏈涢噰绾
绛旓細鈭sinx/(cosx-sinx )dx 1涓洖绛 #鐑# 涓轰粈涔堢幇鍦ㄦ儏鏅枩鍓ц秺鏉ヨ秺灏戜簡?灏瑰叚鍏佸笀 2014-06-04 路 鐭ラ亾鍚堜紮浜烘暀鑲茶瀹 灏瑰叚鍏佸笀 鐭ラ亾鍚堜紮浜烘暀鑲茶瀹 閲囩撼鏁:33776 鑾疯禐鏁:144934 鐧惧己楂樹腑鏁板绔炶禌鏁欑粌, 澶у鏁欐璇勬瘮绗竴鍚, 鏈鍙楀鐢熸杩庢暀 鍚慣A鎻愰棶 绉佷俊TA 鍏虫敞 ...
绛旓細瑙ｇ瓟:琚Н鍑芥暟鐨勫垎姣嶏細 sinx + cosx 瀵瑰垎姣嶈繘琛屽井鍒嗭細 d(sinx + cosx) = (cosx - sinx)dx 琚Н鍑芥暟鐨勫垎瀛愶細 sinx - cosx 琚Н鍑芥暟鐨勫垎瀛愮殑寰垎褰㈠紡锛(sinx - cosx)dx = d(-cosx - sinx) = -d(cosx + sinx)鏁翠釜绉垎鐨勮绠楋細鈭(sinx-cosx)dx/(sinx+cosx) = -鈭玠(sinx+...
