Các bài toán về mối quan hệ giữa hai đường thẳng !!

A.\[\left[ {\vec u,\overrightarrow {u'} } \right] = \vec 0\]

B. \[\left[ {\vec u,\overrightarrow {u'} } \right] = \left[ {\vec u,\overrightarrow {MM'} } \right]\]

C. \[\left[ {\vec u,\overrightarrow {u'} } \right] = \left[ {\vec u,\overrightarrow {MM'} } \right] = \overrightarrow 0 \]

D. \[\left[ {\vec u,\overrightarrow {u'} } \right] \ne \left[ {\vec u,\overrightarrow {MM'} } \right]\]

A.Song song.

B.Trùng nhau.

C.Cắt nhau.

D.Chéo nhau.

A.\(\left\{ {\begin{array}{*{20}{c}}{\left[ {\vec u,\overrightarrow {u'} } \right] \ne \vec 0}\\{\left[ {\vec u,\overrightarrow {u'} } \right]\overrightarrow {MM'} = 0}\end{array}} \right.\)

B. \[\left[ {\vec u,\overrightarrow {u'} } \right] \ne \vec 0\]

C. \[\left[ {\vec u,\overrightarrow {u'} } \right]\overrightarrow {MM'} = 0\]

D. \[\left[ {\vec u,\overrightarrow {u'} } \right] = \vec 0\]

A.d//d′

B.d≡d′

C.d cắt d′

D.d chéo d′

A.Song song.

B.Trùng nhau.

C.Cắt nhau.

D.Chéo nhau.

A.\({d_1}:\left\{ {\begin{array}{*{20}{c}}{x = 3t}\\{y = 1 + t}\\{z = 5t}\end{array}} \right.\)

B. \({d_2}:\left\{ {\begin{array}{*{20}{c}}{x = 2}\\{y = 2 + t}\\{z = 1 + t}\end{array}} \right.\)

C. \[{d_3}:\frac{{x - 2}}{3} = \frac{y}{2} = \frac{{z - 1}}{{ - 5}}\]

D. \[{d_4}:\frac{{x + 2}}{2} = \frac{y}{{ - 1}} = \frac{{z + 1}}{2}\]

A.\[d\left( {A,d'} \right) = \frac{{\left| {\left[ {\overrightarrow {AM'} ,\overrightarrow {u'} } \right]} \right|}}{{\left| {\overrightarrow {u'} } \right|}}\]

B. \[d\left( {A,d'} \right) = \frac{{\left| {\left[ {\overrightarrow {AM'} ,\overrightarrow {u'} } \right]} \right|}}{{\overrightarrow {u'} }}\]

C. \[d\left( {A,d'} \right) = \frac{{\left[ {\overrightarrow {AM'} ,\overrightarrow {u'} } \right]}}{{\overrightarrow {u'} }}\]

D. \[d\left( {A,d'} \right) = \frac{{\left| {\overrightarrow {AM'} .\overrightarrow {u'} } \right|}}{{\left| {\overrightarrow {u'} } \right|}}\]

A.\(\sqrt 2 \)

B. \(\sqrt 3 \)

C. \[2\sqrt 3 \]

D. \[\frac{5}{{\sqrt {17} }}\]

A.\[3\sqrt {19} \]

B. \[\frac{{3\sqrt {19} }}{{13}}\]

C. \[\sqrt 6 \]

D. \[\frac{{\sqrt {66} }}{{11}}\]

A.\[d\left( {{\rm{\Delta }},{\rm{\Delta '}}} \right) = \frac{{\left| {\left[ {\vec u,\overrightarrow {u'} } \right].\overrightarrow {MM'} } \right|}}{{\left| {\left[ {\vec u,\overrightarrow {u'} } \right]} \right|}}\]

B. \[d\left( {{\rm{\Delta }},{\rm{\Delta '}}} \right) = \frac{{\left| {\left[ {\overrightarrow {MM'} ,\overrightarrow {u'} } \right].\vec u} \right|}}{{\left| {\left[ {\vec u,\overrightarrow {u'} } \right]} \right|}}\]

C. \[d\left( {{\rm{\Delta }},{\rm{\Delta '}}} \right) = \frac{{\left| {\left[ {\vec u,\overrightarrow {u'} } \right].\overrightarrow {MM'} } \right|}}{{\left| {\left[ {\vec u,\overrightarrow {MM'} } \right]} \right|}}\]

D. \[d\left( {{\rm{\Delta }},{\rm{\Delta '}}} \right) = \frac{{\left| {\left[ {\vec u,\overrightarrow {u'} } \right].\overrightarrow {MM'} } \right|}}{{\left| {\overrightarrow {MM'} } \right|}}\]

A.9

B.3

C.\(\frac{1}{3}\)

D.1 

A.\[\frac{{x - 1}}{1} = \frac{{y - 2}}{{ - 3}} = \frac{{z - 3}}{{ - 5}}\]

B. \[\frac{{x - 1}}{{ - 1}} = \frac{{y - 2}}{{ - 3}} = \frac{{z - 3}}{{ - 5}}\]

C. \[\frac{{x - 1}}{1} = \frac{{y - 2}}{3} = \frac{{z - 3}}{5}\]

D. \[\frac{{x - 1}}{1} = \frac{{y - 2}}{3} = \frac{{z - 3}}{{ - 5}}\]

A.\[\cos \varphi = \frac{{\left| {\vec u.\overrightarrow {u'} } \right|}}{{\left| {\vec u} \right|.\left| {\overrightarrow {u'} } \right|}}\]

B. \[\cos \varphi = \frac{{\vec u.\overrightarrow {u'} }}{{\left| {\vec u} \right|.\left| {\overrightarrow {u'} } \right|}}\]

C. \[\cos \varphi = - \frac{{\vec u.\overrightarrow {u'} }}{{\left| {\vec u} \right|.\left| {\overrightarrow {u'} } \right|}}\]

D. \[\cos \varphi = - \frac{{\left| {\vec u.\overrightarrow {u'} } \right|}}{{\left| {\vec u} \right|.\left| {\overrightarrow {u'} } \right|}}\]

A.\[\frac{1}{{\sqrt 2 }}\]

B. \[\frac{{\sqrt 2 }}{4}\]

C. \(\frac{1}{2}\)

D. \[\frac{3}{{\sqrt 2 }}\]

A.\(\left[ {\begin{array}{*{20}{c}}{m = 4}\\{m = - 2}\end{array}} \right.\)

B. \(\left[ {\begin{array}{*{20}{c}}{m = - 4}\\{m = 2}\end{array}} \right.\)

C. \(\left[ {\begin{array}{*{20}{c}}{m = 4}\\{m = 2}\end{array}} \right.\)

D. \(\left[ {\begin{array}{*{20}{c}}{m = - 4}\\{m = - 2}\end{array}} \right.\)

A.N(4;0;−1)

B.M(1;−2;3) .           

C.P(7;2;1) .

D.Q(7;2;3)

A.\[\frac{{x - 1}}{5} = \frac{{y - 2}}{{ - 12}} = \frac{{z - 3}}{1}\]

B. \[\frac{{x - 1}}{{ - 5}} = \frac{{y - 2}}{{12}} = \frac{{z - 3}}{1}\]

C. \[\frac{{x - 1}}{5} = \frac{{y - 2}}{{12}} = \frac{{z - 3}}{{ - 1}}\]

D. \[\frac{{x - 1}}{5} = \frac{{y - 2}}{{12}} = \frac{{z - 3}}{1}\]

A.\[\sqrt {29} \]

B. 6

C. 5

D. \[\frac{{\sqrt {34} }}{9}\]

A.(1;1;−3)

B.(1;−1;−1)

C.(1;2;−4)

D. (2;−1;−3)

A.\(\left\{ {\begin{array}{*{20}{c}}{x = 1 + 2t}\\{y = 1 - t}\\{z = - 2 - 2t}\end{array}} \right.\)

B. \(\left\{ {\begin{array}{*{20}{c}}{x = 1 + 2t}\\{y = 1 + t}\\{z = - 2 - 2t}\end{array}} \right.\)

C. \(\left\{ {\begin{array}{*{20}{c}}{x = 2 + t}\\{y = 1 + t}\\{z = 2 - 2t}\end{array}} \right.\)

D. \(\left\{ {\begin{array}{*{20}{c}}{x = 2 + t}\\{y = 1 + t}\\{z = - 2 - 2t}\end{array}} \right.\)

A.\(\Delta :\left\{ {\begin{array}{*{20}{c}}{x = 0}\\{y = - 3t}\\{z = - t}\end{array}} \right.\)

B. \(\Delta :\left\{ {\begin{array}{*{20}{c}}{x = t}\\{y = - 3t}\\{z = t}\end{array}} \right.\)

C. \(\Delta :\left\{ {\begin{array}{*{20}{c}}{x = t}\\{y = - 3t}\\{z = - t}\end{array}} \right.\)

D. \(\Delta :\left\{ {\begin{array}{*{20}{c}}{x = 0}\\{y = - 3t}\\{z = t}\end{array}} \right.\)