Phương trình đường thẳng 2

$$\overrightarrow{u}=\left(3;4;-1\right).$$

$$\overrightarrow{u}=\left(2;-5;2\right).$$

$$\overrightarrow{u}=\left(-2;5;-2\right).$$

$$\overrightarrow{u}=\left(-3;-4;1\right).$$

$$\vec{u}=\left(-1;1;2\right).$$

$$\vec{u}=\left(-1;0;-2\right).$$

$$\vec{u}=\left(-1;0;2\right).$$

$$\vec{u}=\left(1;2;2\right).$$

$$Q\left(2;-1;2\right).$$

$$M\left(-1;-2;-3\right).$$

$$P\left(1;2;3\right).$$

$$N\left(-2;1;-2\right).$$

$$\overrightarrow{u_1}=\left(-1;2;3\right).$$

$$\overrightarrow{u_2}=\left(3;-6;-9\right).$$

$$\overrightarrow{u_3}=\left(1;-2;-3\right).$$

$$\overrightarrow{u_4}=\left(-2;4;3\right).$$

$$\frac{x-2}{1}=\frac{y-1}{2}=\frac{z-1}{3}.$$

$$\frac{x}{2}=\frac{y-1}{1}=\frac{z-2}{-1}.$$

$$\frac{x-1}{-2}=\frac{y+1}{-1}=\frac{z}{-1}.$$

$$\frac{x+2}{2}=\frac{y+1}{-1}=\frac{z+1}{1}.$$

$$\left(-2;1;-3\right).$$

$$\left(-3;2;1\right).$$

$$\left(3;-2;1\right).$$

$$\left(2;1;3\right).$$

$$d:\frac{x+1}{2}=\frac{y}{3}=\frac{z-2}{1}.$$

$$d:\frac{x-1}{1}=\frac{y}{3}=\frac{z+2}{-2}.$$

$$d:\frac{x+1}{2}=\frac{y}{3}=\frac{z-2}{-2}.$$

$$d:\frac{x-1}{2}=\frac{y}{3}=\frac{z+2}{1}.$$

$$\frac{x+1}{-1}=\frac{y-2}{3}=\frac{z+1}{2}.$$

$$\frac{x+1}{1}=\frac{y-3}{-2}=\frac{z-2}{1}.$$

$$\frac{x}{-1}=\frac{y-1}{3}=\frac{z-3}{2}.$$

$$\frac{x}{1}=\frac{y-1}{-2}=\frac{z-3}{1}.$$

$$\left\{x=4+2t;y=-6;z=2-t\right\},t\in R.$$

$$\left\{x=-2+2t;y=-3t;z=1+t\right\},t\in R.$$

$$\left\{x=-2+4t;y=-6t;z=1+2t\right\},t\in R.$$

$$\left\{x=2+2t;y=-3t;z=-1+t\right\},t\in R.$$

Có giá vuông góc với đường thẳng d .

Có giá luôn song song với đường thẳng d.

Có giá luôn trùng với đường thẳng d.

Có giá song song hoặc trùng với đường thẳng d .