• 2022-06-10 问题

    若\( A,B,\left( {A + B} \right) \)为同阶可逆方阵,则\( {\left( { { B^{ - 1}} + {A^{ - 1}}} \right)^{ - 1}} = \)( ) A: \( {B^{ - 1}} + {A^{ - 1}} \) B: \( B + A \) C: \( {\left( {B + A} \right)^{ - 1}} \) D: \( B{\left( {B + A} \right)^{ - 1}}A \)

    若\( A,B,\left( {A + B} \right) \)为同阶可逆方阵,则\( {\left( { { B^{ - 1}} + {A^{ - 1}}} \right)^{ - 1}} = \)( ) A: \( {B^{ - 1}} + {A^{ - 1}} \) B: \( B + A \) C: \( {\left( {B + A} \right)^{ - 1}} \) D: \( B{\left( {B + A} \right)^{ - 1}}A \)

  • 2022-06-15 问题

    函数$y = \ln x$,则${\left( {\ln x} \right)^{\left( n \right)}} = {\left( { - 1} \right)^{n - 1}}{{\left( {n - 1} \right)!} \over {{x^n}}}$。( )

    函数$y = \ln x$,则${\left( {\ln x} \right)^{\left( n \right)}} = {\left( { - 1} \right)^{n - 1}}{{\left( {n - 1} \right)!} \over {{x^n}}}$。( )

  • 2022-06-29 问题

    设\( A,B \)均为\( n \)阶方阵,则必有( ) A: \( \left| {A + B} \right| = \left| A \right| + \left| B \right| \) B: \( AB = BA \) C: \( \left| {AB} \right| = \left| {BA} \right| \) D: \( {\left( {A + B} \right)^{ - 1}} = {A^{ - 1}} + {B^{ - 1}} \)

    设\( A,B \)均为\( n \)阶方阵,则必有( ) A: \( \left| {A + B} \right| = \left| A \right| + \left| B \right| \) B: \( AB = BA \) C: \( \left| {AB} \right| = \left| {BA} \right| \) D: \( {\left( {A + B} \right)^{ - 1}} = {A^{ - 1}} + {B^{ - 1}} \)

  • 2022-06-10 问题

    函数\(y = {\left( { - 2x + 1} \right)^4}\)的导数为( ). A: \( - 8{\left( { - 2x + 1} \right)^3}\) B: \(8{\left( { - 2x + 1} \right)^3}\) C: \(4{\left( { - 2x + 1} \right)^3}\) D: \(- 4{\left( { - 2x + 1} \right)^3}\)

    函数\(y = {\left( { - 2x + 1} \right)^4}\)的导数为( ). A: \( - 8{\left( { - 2x + 1} \right)^3}\) B: \(8{\left( { - 2x + 1} \right)^3}\) C: \(4{\left( { - 2x + 1} \right)^3}\) D: \(- 4{\left( { - 2x + 1} \right)^3}\)

  • 2022-06-14 问题

    若\( A \)是正交矩阵,则\( \left| A \right| = 1 \)或\( \left| A \right| = - 1 \) .

    若\( A \)是正交矩阵,则\( \left| A \right| = 1 \)或\( \left| A \right| = - 1 \) .

  • 2022-06-05 问题

    函数$z=\arcsin\dfrac{1}{~\sqrt{x+y}~}$的定义域为( ) A: $\left\{(x,y)\left|~x+y\geq<br/>0\right.\right\}$; B: $\left\{(x,y)\left|~x+y\geq<br/>1~\text{或}~x+y\leq<br/>-1 \right.\right\}$; C: $\left\{(x,y)\left|~x+y\geq<br/>1\right.\right\}$; D: $\left\{(x,y)\left|~x+y\geq<br/>\dfrac{4}{~\pi^2~}\right.\right\}$.

    函数$z=\arcsin\dfrac{1}{~\sqrt{x+y}~}$的定义域为( ) A: $\left\{(x,y)\left|~x+y\geq<br/>0\right.\right\}$; B: $\left\{(x,y)\left|~x+y\geq<br/>1~\text{或}~x+y\leq<br/>-1 \right.\right\}$; C: $\left\{(x,y)\left|~x+y\geq<br/>1\right.\right\}$; D: $\left\{(x,y)\left|~x+y\geq<br/>\dfrac{4}{~\pi^2~}\right.\right\}$.

  • 2022-10-31 问题

    向量组\(\left( {\matrix{ { - 1} \cr 3 \cr 1 \cr } } \right),\left( {\matrix{ 2 \cr 1 \cr 0 \cr } } \right),\left( {\matrix{ 1 \cr 4 \cr 1 \cr } } \right) \)线性相关.

    向量组\(\left( {\matrix{ { - 1} \cr 3 \cr 1 \cr } } \right),\left( {\matrix{ 2 \cr 1 \cr 0 \cr } } \right),\left( {\matrix{ 1 \cr 4 \cr 1 \cr } } \right) \)线性相关.

  • 2022-07-24 问题

    由\( y = {x^2} - 1,\;y = 0 \)围成的平面图形面积可表示为( )。 A: \( \int_{ - 1}^1 {\left( { - {x^2} + 1} \right)} dx \) B: \( \int_{ - 1}^1 {\left( { { x^2} - 1} \right)} dx \) C: \( \int_0^1 {\left( { - {x^2} + 1} \right)} dx \) D: \( \int_0^1 {\left( { { x^2} - 1} \right)} dx \)

    由\( y = {x^2} - 1,\;y = 0 \)围成的平面图形面积可表示为( )。 A: \( \int_{ - 1}^1 {\left( { - {x^2} + 1} \right)} dx \) B: \( \int_{ - 1}^1 {\left( { { x^2} - 1} \right)} dx \) C: \( \int_0^1 {\left( { - {x^2} + 1} \right)} dx \) D: \( \int_0^1 {\left( { { x^2} - 1} \right)} dx \)

  • 2022-06-16 问题

    求函数$y = \arccos (4x)$的定义域( )。 A: $\left[ { - {1 \over 4},{1 \over 4}} \right]$ B: $\left[ { - 1,1} \right]$ C: $\left[ {0,1} \right]$ D: $\left[ { - 4,4} \right]$

    求函数$y = \arccos (4x)$的定义域( )。 A: $\left[ { - {1 \over 4},{1 \over 4}} \right]$ B: $\left[ { - 1,1} \right]$ C: $\left[ {0,1} \right]$ D: $\left[ { - 4,4} \right]$

  • 2022-05-26 问题

    设 \( A \)为三阶方阵,且\( \left| A \right| = 1 \) ,则 \( \left| {2{A^{ - 1}} - 3{A^*}} \right| = \) A: 1 B: -1 C: 25 D: -25

    设 \( A \)为三阶方阵,且\( \left| A \right| = 1 \) ,则 \( \left| {2{A^{ - 1}} - 3{A^*}} \right| = \) A: 1 B: -1 C: 25 D: -25

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