Cartesian Line 8Fb0Fb
1. **State the problem:** We are given the vector equation of a line:
$$(x, y, z) = (3, -1, 2) + r(3, 2, -4)$$
We need to find the correct Cartesian form of this line from the given options.
2. **Recall the formula:** The vector equation of a line in 3D is:
$$\vec{r} = \vec{r_0} + r\vec{v}$$
where $\vec{r_0} = (x_0, y_0, z_0)$ is a point on the line and $\vec{v} = (a, b, c)$ is the direction vector.
The Cartesian form is:
$$\frac{x - x_0}{a} = \frac{y - y_0}{b} = \frac{z - z_0}{c}$$
3. **Identify components:** From the given equation:
- Point on the line: $(3, -1, 2)$
- Direction vector: $(3, 2, -4)$
4. **Write the Cartesian form:** Substitute values:
$$\frac{x - 3}{3} = \frac{y - (-1)}{2} = \frac{z - 2}{-4}$$
which simplifies to:
$$\frac{x - 3}{3} = \frac{y + 1}{2} = \frac{z - 2}{-4}$$
5. **Match with options:** The denominator for $z$ is $-4$, but the options have $4$ in the denominator. To write with positive denominator, multiply numerator and denominator by $-1$:
$$\frac{z - 2}{-4} = \frac{-(z - 2)}{4} = \frac{-z + 2}{4}$$
6. **Final Cartesian equation:**
$$\frac{x - 3}{3} = \frac{y + 1}{2} = \frac{-z + 2}{4}$$
This matches option D.
**Answer:** Option D is correct.