CJC Vectors Tutorial Q3

Find the line of intersection and acute angle between these two planes.

\(\mathbf{r}=\left( \begin{matrix} 1 \\ 2 \\ 7 \\ \end{matrix} \right)+\lambda \left( \begin{matrix} 1 \\ 1 \\ 0 \\ \end{matrix} \right)+\mu \left( \begin{matrix} 1 \\ 0 \\ 1 \\ \end{matrix} \right)\), \(\lambda \), \(\mu \in \mathbb{R}\) and \(\mathbf{r}=\left( \begin{matrix} 1 \\ 2 \\ 7 \\ \end{matrix} \right)+s\left( \begin{matrix} 1 \\ 2 \\ 4 \\ \end{matrix} \right)+t\left( \begin{matrix} 0 \\ 1 \\ 1 \\ \end{matrix} \right)\), \(s\), \(t\in \mathbb{R}\).