The maximum value of \(f(x) = \left| {\begin{array}{*{20}{c}} {{{\sin }^2}x}&{1 + {{\cos }^2}x}&{\cos 2x} \\ {1 + {{\sin }^2}x}&{{{\cos }^2}x}&{\cos 2x} \\ {{{\sin }^2}x}&{{{\cos }^2}x}&{\sin 2x} \end{array}} \right|\), x ∈ R is:
1
√5
2
5
3
√7
4
\(3\over4\)