Update src/6_eigenvectors_QM.md

src/6_eigenvectors_QM.md

@@ -240,7 +240,7 @@ The set of all the eigenvalues of an operator is called *eigenvalue spectrum* of
 
 3. Find the eigenvalues and eigenvectors of the matrices
 
-    $$A=\begin{pmatrix} -2&-1&-1\\6&3&2\\0&0&1 \end{pmatrix}\,  \quad B=\begin{pmatrix} 1&1&2\\2&2&2\\-1&-1&-1 \end{pmatrix} $$.
+    $$A=\begin{pmatrix} -2&-1&-1\\6&3&2\\0&0&1 \end{pmatrix}\, \quad B=\begin{pmatrix} 1&1&2\\2&2&2\\-1&-1&-1 \end{pmatrix} $$.
 
 4. *The Hadamard gate*