Update src/6_eigenvectors_QM.md

src/6_eigenvectors_QM.md

@@ -67,7 +67,11 @@ the rules of matrix multiplication:
 
 This relations follows from the eigenvalue equation in terms of components
 $$
-\sum_{j=1}^n A_{ij} v_j = \lambda v_i \, ,\quad \to \quad \sum_{j=1}^n A_{ij} v_j - \sum_{j=1}^n\lambda \delta_{ij} v_j =0 \, ,\quad \to \quad \sum_{j=1}^n\left( A_{ij} - \lambda \delta_{ij}\right) v_j =0 \, .
+\begin{array}{r}
+\sum_{j=1}^n A_{ij} v_j = \lambda v_i \, , \\
+\to \quad \sum_{j=1}^n A_{ij} v_j - \sum_{j=1}^n\lambda \delta_{ij} v_j =0 \, ,\\
+\to \quad \sum_{j=1}^n\left( A_{ij} - \lambda \delta_{ij}\right) v_j =0 \, .
+\end{array}
 $$
 Therefore the eigenvalue condition can be written as a set of coupled linear equations
 $$