1. **Problem statement:** Determine the mutual position of the lines \(g\) and \(h\) and find the intersection point if they intersect.
Given:
\[g: \vec{x} = \begin{pmatrix}1 \\ 5 \\ 2\end{pmatrix} + r \cdot \begin{pmatrix}1 \\ 0 \\ 2\end{pmatrix}, \quad h: \vec{x} = \begin{pmatrix}6 \\ 6 \\ 10\end{pmatrix} + s \cdot \begin{pmatrix}3 \\ 1 \\ 4\end{pmatrix}\]
2. **Formula and rules:**
- Two lines intersect if there exist parameters \(r\) and \(s\) such that their position vectors are equal.
- Set \(\vec{x}_g = \vec{x}_h\) and solve for \(r\) and \(s\).
3. **Set up the system:**
\[
\begin{cases}
1 + r = 6 + 3s \\
5 + 0 \cdot r = 6 + s \\
2 + 2r = 10 + 4s
\end{cases}
\]
4. **Rewrite equations:**
\[
\begin{cases}
r - 3s = 5 \\
5 = 6 + s \\
2 + 2r = 10 + 4s
\end{cases}
\]
5. **Solve second equation for \(s\):**
\[
s = 5 - 6 = -1\]
6. **Substitute \(s = -1\) into first equation:**
\[
r - 3(-1) = 5 \implies r + 3 = 5 \implies r = 2\]
7. **Substitute \(r=2\), \(s=-1\) into third equation:**
\[
2 + 2 \cdot 2 = 10 + 4 \cdot (-1) \\
2 + 4 = 10 - 4 \\
6 = 6 \quad \checkmark
\]
8. **Conclusion:**
The parameters satisfy all equations, so the lines intersect.
9. **Find intersection point:**
\[
\vec{x} = \begin{pmatrix}1 \\ 5 \\ 2\end{pmatrix} + 2 \cdot \begin{pmatrix}1 \\ 0 \\ 2\end{pmatrix} = \begin{pmatrix}1 + 2 \\ 5 + 0 \\ 2 + 4\end{pmatrix} = \begin{pmatrix}3 \\ 5 \\ 6\end{pmatrix}\]
**Final answer:**
The lines \(g\) and \(h\) intersect at the point \( (3, 5, 6) \).
Line Intersection Ded722
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.