高一数学题，急~在线=
\u9ad8\u4e00\u6570\u5b66\u9898\u89e3\uff1ay=1-2sinx^2-sinx\uff0c\u56e0\u4e3ax\u5c5e\u4e8e(0,\u03c0/2\u3011,\u6240\u4ee5sinx\u5c5e\u4e8e\uff080\uff0c1\u3011\uff0c\u8bbet=sinx\uff0c y=-2t^2-t+1=-2(t+1/2)^2+3/2\uff0c\u629b\u7269\u7ebf\u5f00\u53e3\u5411\u4e0b\uff0c\u5bf9\u79f0\u8f74x=-1/2\uff0cy\u6700\u5927\u503c\u4e3af(0)=1,y\u6700\u5c0f\u4e3af(1)=-2\uff0c\u6240\u4ee5\u51fd\u6570\u7684\u503c\u57df\u4e3a\u3010-2\uff0c1\uff09
cosacosb－sinasinb＝1/5
cosacosb＋sinasinb＝3/5 整体解方程得
cosacosb＝2/5,sinasinb=1/5
所以tanatanb＝sinasinb/cosacosb=1/2
cos(a+b)=cosacosb-sinasinb=1/5
cos(a-b)=cosacosb+sinasinb=3/5
2cosacosb=4/5
2sinasinb=2/5
tanatanb=sinasinb/cosacosb=1/2
你有那个人教版的中专数学书吗？在第P102就有
绛旓細1銆佹眰閫氳繃鐩寸嚎l:2x+y+4=0鍙婂渾C锛歺²+y²+2x-4y+1=0鐨勪氦鐐癸紝骞朵笖鏈夋渶灏忛潰绉殑鍦咰'鐨勬柟绋嬨傛濊矾锛氬厛姹傚嚭涓や氦鐐笰锛孊,浠B涓虹洿寰勭殑鍦嗛潰绉渶灏忋傝В鏂圭▼缁勶細2x+y+4=0锛 鈶 x²+y²+2x-4y+1=0銆傗憽 鐢扁憼寰梱=-2x-4, 鈶 鎶娾憿浠ｅ叆鈶″緱x²+4x²...
绛旓細1銆 a=(-4+2)/2=-1锛宐=(1+5)/2=3,2銆 F1+F2+F3=(0-3+5,1+2-5)=(2,-2),|F1+F2+F3|=鈭(2^2+(-2)^2)=2鈭2,鍚堝姏鏂瑰悜鏈濅笢鍗45搴︽柟鍚戯紝3銆 鑷崇偣锛3锛2锛夎窛绂讳负1鐨勭偣鐨勮建杩规槸浠ヨ鐐逛负鍦嗗績锛1涓哄崐寰勭殑鍦嗭紝鏂圭▼涓猴細(x-3)^2+(y-2)^2=1.4銆亅a|=鈭歔(1+鈭3...
绛旓細鍦咰鍏充簬鐩寸嚎x+y-1=0瀵圭О,鍒欏渾蹇冨湪鐩寸嚎涓,鍒欐湁:-D/2-E/2-1=0,鍗矰+E+2=0 鍗婂緞涓烘牴鍙2,鍒:鏍瑰彿(D^2+E^2-12)/2=鏍瑰彿2 鏁寸悊寰:D^2+E^2=20 娑堝厓寰桪=4 E=-2 鍦嗙殑鏂圭▼涓: x^2+y^2+4x-2y+3=0 2.璁剧洿绾挎柟绋嬩负x/a+y/b=1 鍗虫槸bx+ay-ab=0 鐩寸嚎涓庡渾鐩稿垏鈥-2a...
绛旓細1銆(x-1)²+(y-2)²=-m+1+4 鏄渾鍒檙²=-m+1+4>0 m<5 2銆佸渾蹇(1,2)鍒扮洿绾胯窛绂=|1+4-4|/鈭(1²+2²)=1/鈭5 寮﹀績璺濇槸1/鈭5锛屽鸡闀4/鈭5 鎵浠ョ敱鍕捐偂瀹氱悊 鍗婂緞r=鈭歔(4/鈭5梅2)²+(1/鈭5)²]=1 鎵浠モ垰(-m+1+4)=1 m=4 ...
绛旓細鈶 搴曟暟澶т簬1锛屾墍浠=2^x鏄鍑芥暟锛屽嵆鏄痽鍑芥暟鐨勫鍖洪棿 y= -x²+x+2鏄绉拌酱x=1/2锛屽紑鍙ｅ悜涓嬬殑鎶涚墿绾匡紝鎵浠鈮1/2鏃堕掑锛寈>1/2鏃堕掑噺 鎵浠ュ嚱鏁癋(x)鐨勫鍖洪棿鏄(锛嶁垶锛1/2]锛屽噺鍖洪棿鏄(1/2锛岋紜鈭)鈶 鐢遍鎰忓彲鐭^2-x-6鈮0,鍗(x-3)(x+2)鈮0,瑙ｅ緱x鈮3, x鈮-2 ...
绛旓細瑙ｇ瓟锛鍦ㄧ嚎鏁板甯姪浣狅紒杩欓涓昏鏄冨療涓や釜鍏紡锛氱涓涓細sin伪+sin尾=2sin[(伪+尾)/2]路cos[(伪-尾)/2]锛涚浜屼釜锛歝os伪+cos尾锛2cos[(伪+尾)/2]路cos[(伪-尾)/2]閭ｄ箞杩欓鐨勮繃绋嬪涓嬶細sin伪+sin尾=2sin[(伪+尾)/2]路cos[(伪-尾)/2]锛1/2 绉诲悜澶勭悊锛歴in[(伪+尾)/2]...
绛旓細1銆 BC鏂圭▼涓猴細(y-2)/x=(10-2)/(-8),y=-x+2,AD鏂圭▼涓猴紝鍏舵枩鐜囦负1 锛(y-4)/(x-1)=1,y=x-3,鐩寸嚎AD涓嶤B鐨勪氦鐐逛负D鐐癸紝x=5/2,y=-1/2,鍚戦噺AD=锛5/2-4锛-1/2-1锛夛紝AD=锛-3/2锛-3/2锛夛紝鍚戦噺AC=锛-12锛9锛夛紝|AC|=鈭歔锛-12锛塣2+9^2]=15,璁綧锛坸0,y0锛,...
绛旓細370116 |鏉ヨ嚜鍥㈤槦鎴戞渶鐖辨暟瀛! |浜屽崄绾ч噰绾崇巼66% 鎿呴暱:鐞嗗伐瀛︾鏁欒偛/绉戝鐧惧害鐭ラ亾鍟嗕笟/鐞嗚储鍘嗗彶璇濋 鍏朵粬绫讳技闂 2011-05-03 楂樹竴鏁板棰 7 2011-04-12 楂樹竴鏁板棰橀樋! 3 2011-04-21 楂樹竴鏁板棰樺湪绾绛,鎬ユ眰 5 2011-04-23 鍑犻亾楂樹竴鏁板棰 1 2011-04-18 楂樹竴鏁板棰!鎬!鍦ㄧ嚎绛 1 鏇村鐩稿叧闂>...
绛旓細绗竴棰橈細f(x)=(2x+a)²-4a-2a² f(0)=-4a-a² f(1)=4-a²褰撳绉拌酱x=-a/2鍦ㄣ0锛1銆戝乏杈,鍗-a/2鈮0鏃讹紝f(x)min=f(0)=g(a)鎵浠ユ鏃秅(a)=-4a-a² a鈭圼0,+鈭瀅 鎵浠ユ鏃秅(a)鐨勫彇鍊艰寖鍥翠负(-鈭,0]锛涘綋瀵圭О杞磝=-a/2鍦ㄣ0锛1銆戝彸杈癸紝...
绛旓細1瑙ｏ細锛1锛夛紙0锛4锛夛紱锛2锛夆垰2+鈭6 锛3锛夎l鍜宭1銆乴2鐩镐氦浜嶮锛坹1锛寉1锛夈丯锛-鈭3y2锛寉2锛夛紝杩嘙銆丯浣渪杞寸殑鍨傜嚎锛屽瀭瓒冲垎鍒槸M'(y1,0锛夈丯鈥欙紙-鈭3y2锛0锛夌敱OP鏄笁瑙掑舰OMN涓嚎寰楋紝OP鏄褰M'N'N寰椾腑浣嶇嚎锛屼笖OM鈥=ON'鈭磞1+y2=8涓攜1=鈭3y2 瑙ｅ緱y1=12-4鈭3锛寉2=4鈭3...
