请教一个高中数学极坐标的题目 高中数学极坐标一道大题。第二问为什么可以那样设，能画图解释一...
\u9ad8\u4e2d\u6570\u5b66\u9898\u76ee\u6781\u5750\u6807 \u8981\u6c42\u8be6\u7ec6\u7b80\u660e\u7684\u7b54\u6848\u5229\u7528\u4f59\u5f26\u5b9a\u7406\u53ef\u5f97\uff1a
\u03c1\uff1d\u6839\u53f7{1^2\uff0b1^2\uff0b\uff0d2\u00d71\u00d71\u00b7cos[\u03c0\uff0d2(\u03c0/4\uff0d\u03b8)]}
\uff1d\u6839\u53f7[2\uff0b2cos(\u03c0/2\uff0d2\u03b8)]
\uff1d2cos(\u03c0/4\uff0d\u03b8)
\u8fd9\u662f\u5706C\u7684\u6781\u5750\u6807\u65b9\u7a0b
\u5f53\u03c1\uff1d1\uff0c\u03b8\uff1d45\u00b0\uff1d\u03c0/4\u65f6\uff0c\u03c1\u00b7sin(\u03b8\uff0b\u03c0)\uff1d1\u00d7sin(\u03c0/4\uff0b\u03c0/4)\uff1d1
\u2234\u76f4\u7ebfL\u7ecf\u8fc7\u5706C\u7684\u5706\u5fc3
\u4ece\u800c\u6240\u6c42\u5f26\u957f\u5c31\u662f\u5706C\u7684\u76f4\u5f84
\u53c8\u6781\u70b9\u5728\u5706C\u4e0a\uff0c\u6545\u5706C\u7684\u534a\u5f84\u4e3a1\uff0c\u76f4\u5f84\u4e3a2\uff0c\u5373\u76f4\u7ebfL\u88ab\u5706C\u622a\u5f97\u7684\u5f26\u957f\u4e3a2
\u2220AOB=\u03c0/3\uff0c\u6240\u4ee5AO,BO\u5939\u89d2\u662f\u5b9a\u503c\u03c0/3\uff0c\u800cA\uff0cB\u9664\u4e86\u5199\u6cd5\u4e0d\u540c\uff0c\u6027\u8d28\u4e0a\u4e00\u6837\uff0c\u6240\u4ee5\u4e0d\u59a8\u5047\u8bbeA\u7684\u03b8\u5750\u6807\u6bd4B\u5c0f\uff0c\u5c31\u53ef\u4ee5\u8bbeA(\u03c11,\u03b8),B(\u03c12,\u03b8+\u03c0/3)\u3002
供参考。
绛旓細瑙ｏ細濡傚浘锛屜侊紳鈭2锛岃鐩寸嚎涓巟杞寸殑澶硅涓何搞傜敱棰樻剰寰梩an胃=1鎴-1銆傗埓胃锛澫/4鎴7蟺/4鈭翠氦鐐圭殑鏋佸潗鏍涓猴紙鈭2锛屜/4锛夋垨(鈭2锛7蟺/4)
绛旓細鍗冲渾蹇冭繃y=x锛屽亣璁惧皢鍦嗙殑鏂圭▼绠鍗曠偣璁撅細x=蟻cos胃,y=蟻sin胃 鍒櫹²=x²+y²锛屽垎鍒唬鍏ュ渾蟻²+k²蟻cos胃+蟻sin胃-k=0锛屽緱x²+y²+k²x-y-k=0锛屽嵆鍖栦负鏍囧噯寮忥細(x-k²/2)²+(y-1/2)²=k+k²/4 姝ゆ椂鍦嗗績k...
绛旓細(x'^2/9)+(y'^2/4)=1 {x=蟻cos胃 {y=蟻sin胃 蟻^2[cos^2(胃)/9]+蟻^2[sin^2(胃)/4)=1 C2鐨鏋佸潗鏍鏂圭▼涓猴細蟻^2[4cos^2(胃)+9sin^2(胃)]/36=1 (2)璁続(蟻1,胃) B(蟻2 , 胃+蟺/2)1/|OA|^2=1/蟻1^=[4cos^2(胃)+9sin^2(胃)]/36 1/|OB|^2=1...
绛旓細鎴戝啓鍦ㄧ焊涓婁簡锛岀湅鍥剧墖鍚э細
绛旓細璁綩涓哄師鐐癸紝BB'涓簒杞达紝B鍧愭爣(-2,0)锛孊'(2,0)锛孭鍧愭爣(0,a)锛孭'鍧愭爣(0,9/a)锛屽垯BP鏂圭▼锛歽=ax/2+a鈥斺斺1 BP'鏂圭▼锛歽=-9x/2a+9/a鈥斺斺2 鐢2灏哸鐢▁銆亂琛ㄧず锛宎=-9(x-2)/2y锛屽甫鍏1锛屽緱鐐筂杞ㄨ抗鏂圭▼锛4y^2+9x^2=36 ...
绛旓細涓よ竟鍚屾椂涔樹互p 鍙緱p^2=-2psinx 鍙緱x^2+y^2=-2y 鍙緱x^2+(y+1)^2=1 鍦嗗績鍧愭爣涓(0,-1)鍦嗗績鐨鏋佸潗鏍涓(1,-蟺/2)閫塨 鏈涢噰绾 璋㈣阿 鏈変换浣曚笉鎳 璇峰姞濂藉弸 涓涓瑙ｇ瓟
绛旓細鍒嗘瀽锛氾紙I锛夊厛灏嗗渾C1锛岀洿绾緾2鍖栨垚鐩磋鍧愭爣鏂圭▼锛屽啀鑱旂珛鏂圭▼缁勮В鍑哄畠浠氦鐐圭殑鐩磋鍧愭爣锛屾渶鍚庡寲鎴鏋佸潗鏍鍗冲彲锛涳紙II锛夌敱锛圛锛夊緱锛孭涓嶲鐐圭殑鍧愭爣鍒嗗埆涓猴紙0锛2锛夛紝锛1锛3锛夛紝浠庤岀洿绾縋Q鐨勭洿瑙掑潗鏍囨柟绋嬩负x-y+2=0锛岀敱鍙傛暟鏂圭▼鍙緱y=bx/2-ab/2+1锛屼粠鑰屾瀯閫犲叧浜巃锛宐鐨勬柟绋嬬粍锛岃В寰梐锛宐鐨勫硷紟瑙ｇ瓟...
绛旓細瑙ｏ細蟻sin(胃-蟺/4)=蟻[sin胃cos(蟺/4)-cos胃sin(蟺/4)]=(鈭2/2)蟻(sin胃-cos胃)=(鈭2/2)(y-x)=鈭2/2;鏁呭緱鏇茬嚎鈶犵殑鐩村緞鍧愭爣鏂圭▼涓: y-x=1锛屽嵆y=x+1...鈶 鐢毕=4sin胃寰椣²=4蟻sin胃锛屽嵆鏈墄²+y²=4y锛涗篃灏辨槸鏈墄²+(y-2)²=4....
绛旓細22銆(1) y-1=tan(蟺/3)(x-3)y=鈭3(x-3)+1 鐩寸嚎L鏂圭▼锛氣垰3x-y+1-3鈭3=0 蟻=4cos胃 蟻^2=4蟻cos胃 x^2+y^2=4x 鏇茬嚎C鏂圭▼锛(x-2)^2+y^2=4 鍦嗗績C(2,0)銆佸崐寰剅=2 C鍒扮洿绾縇鐨勮窛绂伙細d=|2鈭3-0+1-3鈭3|/鈭歔(鈭3)^2+(-1)]=(鈭3-1)/2 (|AB|/2)^2=...
绛旓細浠ュ師鐐逛负鏋佺偣锛寈姝ｅ崐杞翠负鏋佹樇 鍒檡=蟻sin胃锛寈=蟻cos胃 鎵浠ハ乛2sin^2 胃=蟻cos胃 蟻sin^2 胃=cos胃
