关于正态分布，则下列说法不对的是 A: 若$(X_1,X_2,\cdots,X_n)$服从正态分布，则$(X_1,X_2,\cdots,X_n)$各分量之间相互独立 B: 若$(X_1,X_2,\cdots,X_n)$服从正态分布，则$(X_1,X_2,\cdots,X_n)$各分量之间两两不相关 C: 若$(X_1,X_2,\cdots,X_n)$服从正态分布，则$(X_1,X_2,\cdots,X_n)$的每一个分量服从正态分布 D: 若$(X_1,X_2,\cdots,X_n)$的每一个分量服从正态分布，则$(X_1,X_2,\cdots,X_n)$服从正态分布

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2022-05-30 问题

关于正态分布，则下列说法不对的是 A: 若$(X_1,X_2,\cdots,X_n)$服从正态分布，则$(X_1,X_2,\cdots,X_n)$各分量之间相互独立 B: 若$(X_1,X_2,\cdots,X_n)$服从正态分布，则$(X_1,X_2,\cdots,X_n)$各分量之间两两不相关 C: 若$(X_1,X_2,\cdots,X_n)$服从正态分布，则$(X_1,X_2,\cdots,X_n)$的每一个分量服从正态分布 D: 若$(X_1,X_2,\cdots,X_n)$的每一个分量服从正态分布，则$(X_1,X_2,\cdots,X_n)$服从正态分布

2022-06-07 问题

Which one of the following sequences has a finite limit? A: $\ln(n),\;n=1,2,\cdots$ B: $\ln(\sin(n)),\;n=1,2,\cdots$ C: $\sqrt{n^2-1}-n^{1/3},\;n=1,2,\cdots$ D: $ \sin\frac{1}{n},\;n=1,2,\cdots$

2022-06-30 问题

下列定义的映射中， ___ 不是内积. A: $\langle x,y \rangle \triangleq xy ,x,y \in \mathbb{R}$ B: $\langle (x_1,\cdots,x_n),(y_1,\cdots,y_n) \rangle \triangleq \Sigma_{i=1}^{n}x_iy_i,(x_1,\cdots,x_n),(y_1,\cdots,y_n)\in \mathbb{R}^n$ C: $\langle f,g \rangle \triangleq \int_a^b f(x)g(x)\mathrm{d}x ,f,g \in C([a,b])$（$[a,b]$上连续实函数全体） D: $\langle (x_1,\cdots,x_n),(y_1,\cdots,y_n) \rangle \triangleq \Sigma_{i,j=1}^{n}a_{ij}x_iy_i,(x_1,\cdots,x_n),(y_1,\cdots,y_n)\in \mathbb{R}^n,A = (a_{ij})是实对称方阵$

下列定义的映射中， ___ 不是内积. A: $\langle x,y \rangle \triangleq xy ,x,y \in \mathbb{R}$ B: $\langle (x_1,\cdots,x_n),(y_1,\cdots,y_n) \rangle \triangleq \Sigma_{i=1}^{n}x_iy_i,(x_1,\cdots,x_n),(y_1,\cdots,y_n)\in \mathbb{R}^n$ C: $\langle f,g \rangle \triangleq \int_a^b f(x)g(x)\mathrm{d}x ,f,g \in C([a,b])$（$[a,b]$上连续实函数全体） D: $\langle (x_1,\cdots,x_n),(y_1,\cdots,y_n) \rangle \triangleq \Sigma_{i,j=1}^{n}a_{ij}x_iy_i,(x_1,\cdots,x_n),(y_1,\cdots,y_n)\in \mathbb{R}^n,A = (a_{ij})是实对称方阵$

2022-06-15 问题

若函数$f(x)$满足条件：$f(x+\pi)=-f(x)$, 则在$(-\pi,\pi)$内的傅里叶级数满足下列哪个特性？ A: $a_{2n}=b_{2n}=0, (n=1,2,\cdots)$ B: $a_{2n-1}=b_{2n-1}=0, (n=1,2,\cdots)$ C: $a_{2n-1}=b_{2n}=0, (n=1,2,\cdots)$ D: $a_{2n}=b_{2n-1}=0, (n=1,2,\cdots)$

若函数$f(x)$满足条件：$f(x+\pi)=-f(x)$, 则在$(-\pi,\pi)$内的傅里叶级数满足下列哪个特性？ A: $a_{2n}=b_{2n}=0, (n=1,2,\cdots)$ B: $a_{2n-1}=b_{2n-1}=0, (n=1,2,\cdots)$ C: $a_{2n-1}=b_{2n}=0, (n=1,2,\cdots)$ D: $a_{2n}=b_{2n-1}=0, (n=1,2,\cdots)$

2022-06-27 问题

牛顿迭代法的迭代格式以下正确的是： A: ${x_{k + 1}} = {x_k} - {{f({x_k})} \over {f'({x_k})}},k = 0,1, \cdots $ B: ${x_{k + 1}} = {x_k} - {{f'({x_k})} \over {f({x_k})}},k = 0,1, \cdots $ C: ${x_{k + 1}} = {x_k} - {{f'({x_{k + 1}})} \over {f({x_k})}},k = 0,1, \cdots $ D: ${x_{k + 1}} = {x_k} - {{f({x_{k + 1}})} \over {f'({x_k})}},k = 0,1, \cdots $

牛顿迭代法的迭代格式以下正确的是： A: ${x_{k + 1}} = {x_k} - {{f({x_k})} \over {f'({x_k})}},k = 0,1, \cdots $ B: ${x_{k + 1}} = {x_k} - {{f'({x_k})} \over {f({x_k})}},k = 0,1, \cdots $ C: ${x_{k + 1}} = {x_k} - {{f'({x_{k + 1}})} \over {f({x_k})}},k = 0,1, \cdots $ D: ${x_{k + 1}} = {x_k} - {{f({x_{k + 1}})} \over {f'({x_k})}},k = 0,1, \cdots $

2022-06-15 问题

排列$ n123 \cdots (n - 1) $的逆序数为$ n - 1 $.

2022-05-31 问题

求方程$x = \cos x$根的牛顿迭代公式是。 A: ${x_{n + 1}} = {x_n} - { { {x_n} - \cos {x_n}} \over {1 + \sin {x_n}}},n = 0,1,2 \cdots $ B: ${x_{n + 1}} = {x_n} + { { {x_n} - \cos {x_n}} \over {1 + \sin {x_n}}},n = 0,1,2 \cdots $ C: ${x_{n + 1}} = {x_n} - { { {x_n} - \sin {x_n}} \over {1 + \sin {x_n}}},n = 0,1,2 \cdots $ D: ${x_{n + 1}} = {x_n} - { { {x_n} - \cos {x_n}} \over {1 + \cos{x_n}}},n = 0,1,2 \cdots $

求方程$x = \cos x$根的牛顿迭代公式是。 A: ${x_{n + 1}} = {x_n} - { { {x_n} - \cos {x_n}} \over {1 + \sin {x_n}}},n = 0,1,2 \cdots $ B: ${x_{n + 1}} = {x_n} + { { {x_n} - \cos {x_n}} \over {1 + \sin {x_n}}},n = 0,1,2 \cdots $ C: ${x_{n + 1}} = {x_n} - { { {x_n} - \sin {x_n}} \over {1 + \sin {x_n}}},n = 0,1,2 \cdots $ D: ${x_{n + 1}} = {x_n} - { { {x_n} - \cos {x_n}} \over {1 + \cos{x_n}}},n = 0,1,2 \cdots $

2021-04-14 问题

Which one of the following sequences has a finite limit? A: $\ln(n),\;n=1,2,\cdots$ B: $\ln(\sin(n)),\;n=1,2,\cdots$ C: $\sqrt{n^2-1}-n^{1/3},\;n=1,2,\cdots$ D: $ \sin\frac{1}{n},\;n=1,2,\cdots$

若函数$f(x)$满足条件：$f(x+\pi)=-f(x)$, 则在$(-\pi,\pi)$内的傅里叶级数满足下列哪个特性？ A: $a_{2n}=b_{2n}=0, (n=1,2,\cdots)$ B: $a_{2n-1}=b_{2n-1}=0, (n=1,2,\cdots)$ C: $a_{2n-1}=b_{2n}=0, (n=1,2,\cdots)$ D: $a_{2n}=b_{2n-1}=0, (n=1,2,\cdots)$

排列\( n123 \cdots (n - 1) \)的逆序数为\( n - 1 \).

向量组`\alpha _1,\alpha _2, \cdots ,\alpha _m`线性相关的充要条件是()

(1). 请问视频例中，\( Z=\max (X_1 ,X_2 ,\cdots ,X_n ) \) 的期望为()。

若果`R(alpha_1,alpha_2,cdots,alpha_n)=4`，则下列说法正确的是（） </p></p>

Which one of the following sequences has a finite limit? A: $\ln(n),\;n=1,2,\cdots$ B: $\ln(\sin(n)),\;n=1,2,\cdots$ C: $\sqrt{n^2-1}-n^{1/3},\;n=1,2,\cdots$ D: $ \sin\frac{1}{n},\;n=1,2,\cdots$

若函数$f(x)$满足条件：$f(x+\pi)=-f(x)$, 则在$(-\pi,\pi)$内的傅里叶级数满足下列哪个特性？ A: $a_{2n}=b_{2n}=0, (n=1,2,\cdots)$ B: $a_{2n-1}=b_{2n-1}=0, (n=1,2,\cdots)$ C: $a_{2n-1}=b_{2n}=0, (n=1,2,\cdots)$ D: $a_{2n}=b_{2n-1}=0, (n=1,2,\cdots)$

排列\( n123 \cdots (n - 1) \)的逆序数为\( n - 1 \).

向量组`\alpha _1,\alpha _2, \cdots ,\alpha _m`线性相关的充要条件是()

(1). 请问视频例中，\( Z=\max (X_1 ,X_2 ,\cdots ,X_n ) \) 的期望为()。

若果`R(alpha_1,alpha_2,cdots,alpha_n)=4`，则下列说法正确的是（ ） </p></p>

若果`R(alpha_1,alpha_2,cdots,alpha_n)=4`，则下列说法正确的是（） </p></p>