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        1. 15.已知雙曲線的右焦點(diǎn)是橢圓的一個(gè)頂點(diǎn).則 查看更多

           

          題目列表(包括答案和解析)

          已知雙曲線,點(diǎn)分別為雙曲線的左、右焦點(diǎn),動(dòng)點(diǎn)軸上方.

          (1)若點(diǎn)的坐標(biāo)為是雙曲線的一條漸近線上的點(diǎn),求以、為焦點(diǎn)且經(jīng)過(guò)點(diǎn)的橢圓的方程;

          (2)若∠,求△的外接圓的方程;

          (3)若在給定直線上任取一點(diǎn),從點(diǎn)向(2)中圓引一條切線,切點(diǎn)為. 問(wèn)是否存在一個(gè)定點(diǎn),恒有?請(qǐng)說(shuō)明理由.

           

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          已知雙曲線,點(diǎn)、分別為雙曲線的左、右焦點(diǎn),動(dòng)點(diǎn)軸上方.
          (1)若點(diǎn)的坐標(biāo)為是雙曲線的一條漸近線上的點(diǎn),求以、為焦點(diǎn)且經(jīng)過(guò)點(diǎn)的橢圓的方程;
          (2)若∠,求△的外接圓的方程;
          (3)若在給定直線上任取一點(diǎn),從點(diǎn)向(2)中圓引一條切線,切點(diǎn)為. 問(wèn)是否存在一個(gè)定點(diǎn),恒有?請(qǐng)說(shuō)明理由.

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          已知雙曲線,點(diǎn)、分別為雙曲線的左、右焦點(diǎn),動(dòng)點(diǎn)軸上方.
          (1)若點(diǎn)的坐標(biāo)為是雙曲線的一條漸近線上的點(diǎn),求以為焦點(diǎn)且經(jīng)過(guò)點(diǎn)的橢圓的方程;
          (2)若∠,求△的外接圓的方程;
          (3)若在給定直線上任取一點(diǎn),從點(diǎn)向(2)中圓引一條切線,切點(diǎn)為. 問(wèn)是否存在一個(gè)定點(diǎn),恒有?請(qǐng)說(shuō)明理由.

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          已知雙曲線x2-y2=4a(a∈R,a≠0)的右焦點(diǎn)是橢圓
          x2
          16
          +
          y2
          9
          =1
          的一個(gè)頂點(diǎn),則a=______.

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          已知雙曲線x2-y2=4a(a∈R,a≠0)的右焦點(diǎn)是橢圓的一個(gè)頂點(diǎn),則a=   

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          1-10.CDBBA   CACBD

          11.6ec8aac122bd4f6e 12. ①③④   13.-2或1  14. 6ec8aac122bd4f6e、6ec8aac122bd4f6e  15.2  16. 6ec8aac122bd4f6e 17.6ec8aac122bd4f6e.

          18.

          解:(1)由已知6ec8aac122bd4f6e6ec8aac122bd4f6e          7分

          (2)由6ec8aac122bd4f6e                                                                   10分

          由余弦定理得6ec8aac122bd4f6e                          14分

           

          19.(1)證明:∵PA⊥底面ABCD,BC6ec8aac122bd4f6e平面AC,∴PA⊥BC,                                  3分

          ∵∠ACB=90°,∴BC⊥AC,又PA∩AC=A,∴BC⊥平面PAC.                             5分

          (2)解:過(guò)C作CE⊥AB于E,連接PE,

          ∵PA⊥底面ABCD,∴CE⊥面PAB,

          ∴直線PC與平面PAB所成的角為6ec8aac122bd4f6e,                                                     10分

          ∵AD=CD=1,∠ADC=60°,∴AC=1,PC=2,

          6ec8aac122bd4f6e中求得CE=6ec8aac122bd4f6e,∴6ec8aac122bd4f6e.                                                  14分

           

          6ec8aac122bd4f6e20.解:(1)由6ec8aac122bd4f6e①,得6ec8aac122bd4f6e②,

          ②-①得:6ec8aac122bd4f6e.                              4分

          (2)由6ec8aac122bd4f6e求得6ec8aac122bd4f6e.          7分

          6ec8aac122bd4f6e,6ec8aac122bd4f6e   11分

          6ec8aac122bd4f6e

          6ec8aac122bd4f6e.                                                                 14分

           

          21.解:

          (1)由6ec8aac122bd4f6e得c=1                                                                                       1分

          6ec8aac122bd4f6e,                                                         4分

          6ec8aac122bd4f6e6ec8aac122bd4f6e

          6ec8aac122bd4f6e                                                                                        5分

          (2)6ec8aac122bd4f6e6ec8aac122bd4f6e,6ec8aac122bd4f6e時(shí)取得極值.由6ec8aac122bd4f6e6ec8aac122bd4f6e6ec8aac122bd4f6e6ec8aac122bd4f6e.                                                                                          8分

          6ec8aac122bd4f6e,6ec8aac122bd4f6e,∴當(dāng)6ec8aac122bd4f6e時(shí),6ec8aac122bd4f6e,

          6ec8aac122bd4f6e6ec8aac122bd4f6e上遞減.                                                                                       12分

          6ec8aac122bd4f6e∴函數(shù)6ec8aac122bd4f6e的零點(diǎn)有且僅有1個(gè)     15分

           

          22.解:(1) 設(shè)6ec8aac122bd4f6e,由已知6ec8aac122bd4f6e

          6ec8aac122bd4f6e,                                        2分

          設(shè)直線PB與圓M切于點(diǎn)A,6ec8aac122bd4f6e

          6ec8aac122bd4f6e,

          6ec8aac122bd4f6e6ec8aac122bd4f6e                                                 6分

          (2) 6ec8aac122bd4f6e點(diǎn) B(0,t),點(diǎn)6ec8aac122bd4f6e,                                                                7分

          進(jìn)一步可得兩條切線方程為:

          6ec8aac122bd4f6e,                                   9分

          6ec8aac122bd4f6e6ec8aac122bd4f6e,6ec8aac122bd4f6e,

          6ec8aac122bd4f6e6ec8aac122bd4f6e,                                          13分

          6ec8aac122bd4f6e,又6ec8aac122bd4f6e時(shí),6ec8aac122bd4f6e,

          6ec8aac122bd4f6e6ec8aac122bd4f6e面積的最小值為6ec8aac122bd4f6e                                                                            15分

           

           


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