The values of x for which the given matrix\(\left[ {\begin{array}{*{20}{c}} {{\rm{ - x}}}&{\rm{x}}&{\rm{2}}\\ {\rm{2}}&{\rm{x}}&{{\rm{ - x}}}\\ {\rm{x}}&{{\rm{ - 2}}}&{{\rm{ - x}}} \end{array}} \right]\) will be non-singular are
1
-2 ≤ x ≤ 2
2
For all x other than 2 and -2
3
x ≥ 2
4
x ≤ -2