Câu hỏi:

Đường thẳng đi qua điểm $\left(-{\mathrm{x}}_0;-{\mathrm{y}}_0;-{\mathrm{z}}_0\right)$ và có VTCP $\left(-\mathrm{a};-\mathrm{b};-\mathrm{c}\right)$ có phương trình:

A. $\frac{\mathrm{x}-{\mathrm{x}}_0}{\mathrm{a}}=\frac{\mathrm{y}-{\mathrm{y}}_0}{\mathrm{b}}=\frac{\mathrm{z}-{\mathrm{z}}_0}{\mathrm{c}}$

B. B. $\frac{\mathrm{x}-{\mathrm{x}}_0}{-\mathrm{a}}=\frac{\mathrm{y}-{\mathrm{y}}_0}{-\mathrm{b}}=\frac{\mathrm{z}-{\mathrm{z}}_0}{-\mathrm{c}}$

C. C. $\frac{\mathrm{x}+{\mathrm{x}}_0}{\mathrm{a}}=\frac{\mathrm{y}+{\mathrm{y}}_0}{\mathrm{b}}=\frac{\mathrm{z}+{\mathrm{z}}_0}{\mathrm{c}}$

D. D. $\frac{\mathrm{x}+{\mathrm{x}}_0}{\mathrm{a}}=\frac{\mathrm{y}+{\mathrm{y}}_0}{-\mathrm{b}}=\frac{\mathrm{z}+{\mathrm{z}}_0}{\mathrm{c}}$

Câu 1:

Phương trình tham số của đường thẳng đi qua điểm $\mathrm{M}\left({\mathrm{x}}_0;{\mathrm{y}}_0;{\mathrm{z}}_0\right)$ và có VTCP $\overrightarrow{\mathrm{u}}=\left(\mathrm{a};\mathrm{b};\mathrm{c}\right)$ là:

A. $\mathrm{d}:\left\{\begin{array}{c}\mathrm{x}={\mathrm{x}}_0+\mathrm{at}\\ \mathrm{y}={\mathrm{y}}_0+\mathrm{bt}\\ \mathrm{z}={\mathrm{z}}_0+\mathrm{ct}\end{array}\right.\left(\mathrm{t}\in \mathrm{Z}\right)$

B. B. $\mathrm{d}:\left\{\begin{array}{c}\mathrm{x}={\mathrm{x}}_0+\mathrm{at}\\ \mathrm{y}={\mathrm{y}}_0+\mathrm{bt}\\ \mathrm{z}={\mathrm{z}}_0+\mathrm{ct}\end{array}\right.\left(\mathrm{t}\in \mathrm{R}\right)$

C. C. $\mathrm{d}:\left\{\begin{array}{c}\mathrm{x}=\mathrm{a}+{\mathrm{x}}_0\mathrm{t}\\ \mathrm{y}=\mathrm{b}+{\mathrm{y}}_0\mathrm{t}\\ \mathrm{z}=\mathrm{c}+{\mathrm{z}}_0\mathrm{t}\end{array}\right.\left(\mathrm{t}\in \mathrm{R}\right)$

D. D. $\mathrm{d}:\left\{\begin{array}{c}\mathrm{x}=\mathrm{a}+{\mathrm{x}}_0\mathrm{t}\\ \mathrm{y}=\mathrm{b}+{\mathrm{y}}_0\mathrm{t}\\ \mathrm{z}=\mathrm{c}+{\mathrm{z}}_0\mathrm{t}\end{array}\right.\left(\mathrm{t}\in \mathrm{Z}\right)$

Câu 2:

Trong không gian Oxyz, tìm phương trình tham số trục Ox?

A. $\left\{\begin{array}{c}\mathrm{x}=\mathrm{t}\\ \mathrm{y}=\mathrm{t}\\ \mathrm{z}=\mathrm{t}\end{array}\right.\left(\mathrm{t}\in \mathrm{R}\right)$

B. B. $\left\{\begin{array}{c}\mathrm{x}=\mathrm{t}\\ \mathrm{y}=0\\ \mathrm{z}=0\end{array}\right.\left(\mathrm{t}\in \mathrm{R}\right)$

C. C. $\left\{\begin{array}{c}\mathrm{x}=\mathrm{t}\\ \mathrm{y}=\mathrm{t}\\ \mathrm{z}=0\end{array}\right.\left(\mathrm{t}\in \mathrm{R}\right)$

D. D. $\left\{\begin{array}{c}\mathrm{x}=0\\ \mathrm{y}=0\\ \mathrm{z}=\mathrm{t}\end{array}\right.\left(\mathrm{t}\in \mathrm{R}\right)$

Câu 3:

Cho d, d’ là các đường thẳng có VTCP lần lượt là $\overrightarrow{\mathrm{u}},\overrightarrow{\mathrm{u}\text{'}}$. Nếu $\left[\overrightarrow{\mathrm{u}},\overrightarrow{\mathrm{u}\text{'}}\right]=\overrightarrow{0}$ thì:

A. $\mathrm{d}//\mathrm{d}\text{'}$

B. B. $\mathrm{d}\equiv \mathrm{d}\text{'}$

C. d cắt d’

D. A hoặc B đúng

Câu 4:

Trong không gian Oxyz, tìm phương trình tham số trục Oz?

A. $\left\{\begin{array}{c}\mathrm{x}=\mathrm{t}\\ \mathrm{y}=\mathrm{t}\\ \mathrm{z}=\mathrm{t}\end{array}\right.$

B. B. $\left\{\begin{array}{c}\mathrm{x}=\mathrm{t}\\ \mathrm{y}=0\\ \mathrm{z}=0\end{array}\right.$

C. C. $\left\{\begin{array}{c}\mathrm{x}=\mathrm{t}\\ \mathrm{y}=\mathrm{t}\\ \mathrm{z}=0\end{array}\right.$

D. D. $\left\{\begin{array}{c}\mathrm{x}=0\\ \mathrm{y}=0\\ \mathrm{z}=\mathrm{t}\end{array}\right.$

Câu 5:

Góc giữa hai đường thẳng có các VTCP lần lượt là $\overrightarrow{\mathrm{u}},\overrightarrow{\mathrm{u}\text{'}}$ thỏa mãn:

A. $\mathrm{cos\phi }=\frac{\left|\overrightarrow{\mathrm{u}}.\overrightarrow{\mathrm{u}\text{'}}\right|}{\left|\overrightarrow{\mathrm{u}}\right|.\left|\overrightarrow{\mathrm{u}\text{'}}\right|}$

B. B. $\mathrm{cos\phi }=\frac{\overrightarrow{\mathrm{u}}.\overrightarrow{\mathrm{u}\text{'}}}{\left|\overrightarrow{\mathrm{u}}\right|.\left|\overrightarrow{\mathrm{u}\text{'}}\right|}$

C. C. $\mathrm{cos\phi }=-\frac{\overrightarrow{\mathrm{u}}.\overrightarrow{\mathrm{u}\text{'}}}{\left|\overrightarrow{\mathrm{u}}\right|.\left|\overrightarrow{\mathrm{u}\text{'}}\right|}$

D. D. $\mathrm{cos\phi }=-\frac{\left|\overrightarrow{\mathrm{u}}.\overrightarrow{\mathrm{u}\text{'}}\right|}{\left|\overrightarrow{\mathrm{u}}\right|.\left|\overrightarrow{\mathrm{u}\text{'}}\right|}$

Câu 6:

Cho d, d’ là các đường thẳng có VTCP lần lượt là $\overrightarrow{\mathrm{u}},\overrightarrow{\mathrm{u}\text{'}},\mathrm{M}\in \mathrm{d},\mathrm{M}\in \mathrm{d}\text{'}$. Khi đó $\mathrm{d}\equiv \mathrm{d}\text{'}$ nếu:

A. $\left[\overrightarrow{\mathrm{u}},\overrightarrow{\mathrm{u}\text{'}}\right]=\overrightarrow{0}$

B. B. $\left[\overrightarrow{\mathrm{u}},\overrightarrow{\mathrm{u}\text{'}}\right]=\left[\overrightarrow{\mathrm{u}},\overrightarrow{\mathrm{MM}\text{'}}\right]$

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

D. D. $\left[\overrightarrow{\mathrm{u}},\overrightarrow{\mathrm{u}\text{'}}\right]\ne \left[\overrightarrow{\mathrm{u}},\overrightarrow{\mathrm{MM}\text{'}}\right]$