解题方法
1 . 生物的性状是由遗传因子决定的.每个因子决定着一种特定的性状,其中决定显性性状的为高茎遗传因子,用大写字母(如
)来表示;决定隐性性状的为矮茎遗传因子,用小写字母(如
)来表示.如图,在孟德尔豌豆试验中,
的基因型为Dd,子二代
的基因型为DD,Dd,dd,且这三种基因型的比为
如果在子二代中任意选取2颗豌豆进行杂交试验,则子三代
中高茎的概率为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5076289823db419f94e9c0c8f4aafd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3fb78c5f885034612c0e030b920143d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1ade08283ce891e7498ba7d5b5cbce2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1282962a17a48a18edf733204054d67.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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解题方法
2 . 若数列
满足
,
的前
项和为
,则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e77508401eb0f81e19ef3eb3444240c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
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解题方法
3 . 已知函数
,若
,则
的取值( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/324c31fdada4c31ce6107a2bc21760ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/147f89995c5aa07ce7f797c308c9c7d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/450398974b1561ca801e102e16df6789.png)
A.一定为正 | B.一定为负 | C.一定为零 | D.正、负、零都可能 |
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4 . 如图,一个正八面体的八个面分别标以数字1到8,任意抛掷一次这个正八面体,观察它与地面接触的面上的数字
,得到样本空间
,设事件
为奇数
,事件
,事件
,则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/311314491bc52778b4d1c1765894d0ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e171f08a189e8a75094dead09255738f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4ca8bdc812627d925f00ed7c145d696.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94f8529f8e623e55061a44ff5d5050a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a0ace1a8c22a0e1de183642a54a0af5.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
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5 . 某高校统计的连续5天入校参观的人数(单位:千人)如下:
并计算得,
.
(1)求
关于
的回归直线方程,并预测第10天入校参观的人数;
(2)已知该校开放1号,2号门供参观者进出,参观者从这两处门进校的概率相同,且从进校处的门离校的概率为
,从另一处门离校的概率为
.假设甲、乙两名参观者进出该校互不影响,已知甲、乙两名参观者从1号门离校,求他们从不同门进校的概率.
附:回归直线方程
,其中
.
样本号 | 1 | 2 | 3 | 4 | 5 |
第 | 1 | 2 | 3 | 4 | 5 |
参观人数 | 2.4 | 2.7 | 4.1 | 6.4 | 7.9 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/985f1673ddf7ed5872c91f01ba8eef01.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
(2)已知该校开放1号,2号门供参观者进出,参观者从这两处门进校的概率相同,且从进校处的门离校的概率为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf31876698721a199c7c53c6b320aa86.png)
附:回归直线方程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1db6103cb0f1d2bd6b19235d53ee7e98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/446c21b8025405469a473aa0b32f9373.png)
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6 . 已知函数
(
)的图象关于直线
对称,若存在
,使得
(其中
,
),则
的最小值为______
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58d566cc50283930e80764affd45c5f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20849c00c47cbdc43f18d53341b6c4e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8973254e0eeb29a0add0e4677ce5337b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fe1c31a81f198c443e71b83ca662939.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b965dbffd61b1e3e3c6f3ecd00b377e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0704f453b2de48d36911f7db496bbf82.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a37a59558292ad6b3d0978bfd7484990.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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解题方法
7 . 直四棱柱
的所有棱长都为
,
,点
在四边形
及其内部运动,且满足
,则点
到平面
的距离的最小值为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8bbaccd578a43b2397c8bdd50592fa07.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2bf9ef324f1289e205e29fed105c38e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f88e265ee000aed605e9fdf328745930.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15b78c047642924fe864028c81b1f49d.png)
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解题方法
8 . 棱长为2的正方体
中,设点
为底面
内(含边界)的动点,则点
到平面
距离之和的最小值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632f2bf1cd0435041fa04b01901d1c8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b04d6165b18f1a031b2a137961832491.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f571a1aac46c6d0cf440c0ec2846bf9.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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9 . 已知
,向量
,且满足![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcb6a037ca43e342496f5b00870a8689.png)
(1)求点
的坐标;
(2)若点
在直线
(
为坐标原点)上运动,当
取最小值时,求点
的坐标.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/baba5942e11975cd2383393d7e619136.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7199e5758b135764a980570891013940.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcb6a037ca43e342496f5b00870a8689.png)
(1)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
(2)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef4113c492885ba7c47fe42ac792578f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7787dfab61ed9830b531da365e592bbd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
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解题方法
10 . 在直角三角形
中,
,点
在边
上,且
,设
.
(1)若
,求
的值;
(2)若
,求
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8652515789d01ab3af8c9986cf94274a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/379556ae8865fdf6430f71be2a99f71e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf718980f931b3f21a332916404fef2f.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/759b29a7b2b3735306f1a650355a7858.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ee25a78681febe00db64902902420ea.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e65397f11ea8af736f38debadf420c4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da336bc7d2112ecff7d1e632ea2df748.png)
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