设随机变量X和Y独立同分布，记
，则随机变量U与V必然（）.
A: 相关系数不为零
B: 独立
C: 不独立
D: 相关系数为零
，则随机变量U与V必然（）.A: 相关系数不为零
B: 独立
C: 不独立
D: 相关系数为零
举一反三
- (12). 设随机变量 \( X \) 与 \( Y \) 独立同分布，记 \( U=X-Y \)，\( V=X+Y \)，则随机变量 \( U \) 与 \( V \) 必然（ ）。 A: 不独立； B: 独立； C: 相关系数不为零； D: 相关系数为零。
- 图示结构，汇交于结点A各杆端的力矩分配系数为：（）<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/d8fb108baf5043489469508c124eabc9.png"> A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/71af4aae8d3c4cc3a8236715c02d8dd0.png">,<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/ccfc76583f3a4a17a1b8ae5d350c35c7.png">,<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/0f214a006bf64228879035c5c64fba2a.png"> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/f6e2d4cb58c943b19e51aa37b929a34d.png">,<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/7b66a4d0913142fabfdc2805b2971ecb.png">,<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/54e6491e78754550be4f562e0849acd0.png"> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/115a0df0ea124266ae250912e8b572a1.png">,<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/b686ba286d90499a9729e57a8fea8e32.png">,<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/5c1a3965cc7245a0a9bca5f2eae645bf.png"> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/3b342699d2aa451d9a227dff4928c65f.png">,<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/1d9ea5da536a4f18bd677cead25f28b2.png">
- 设随机变量[img=19x17]17e4360d379491b.png[/img]和[img=15x17]17e4360d3ed60d4.png[/img]独立同分布,记[img=73x19]17e43783a5b5f55.png[/img],[img=72x19]17e43783b420a3f.png[/img],则随机变量[img=17x19]17e43783bbcd9d4.png[/img]和[img=16x19]17e4373a0574867.png[/img]必然() A: 独立; B: 不独立; C: 相关不为零; D: 相关系数为零。
- 设随机变量X与Y独立同分布，记U = X-Y，V = X + Y，则随机变量U与V必然（）．
- 下列结论错误的是（） A: 若<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/f6523f26b0ca417294d239696ec45367.png">在<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/4a3d4acefd7f4477a8e87e2ae428b31a.png">处连续，则<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/f6523f26b0ca417294d239696ec45367.png">在<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/091d1b1af4704a85b8293d2fd567adbf.png">处可导. B: 若<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/f6523f26b0ca417294d239696ec45367.png">在<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/f6a503657edf44fb88c8b115537832ae.png">处不连续，则<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/f6523f26b0ca417294d239696ec45367.png">在<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/091d1b1af4704a85b8293d2fd567adbf.png">处不可导. C: 若<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/f6523f26b0ca417294d239696ec45367.png">在<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/f6a503657edf44fb88c8b115537832ae.png">处可导，则<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/f6523f26b0ca417294d239696ec45367.png">在<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/091d1b1af4704a85b8293d2fd567adbf.png">处连续. D: 若<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/f6523f26b0ca417294d239696ec45367.png">在<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/f6a503657edf44fb88c8b115537832ae.png">处不可导，则<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/f6523f26b0ca417294d239696ec45367.png">在<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202007/091d1b1af4704a85b8293d2fd567adbf.png">处也可能连续.