The maximum value of $f ( x ) = \left| \begin{array} { c c c } \sin ^ { 2 } x & 1 + \cos ^ { 2 } x & \cos 2x \\ 1 + \sin ^ { 2 } x & \cos ^ { 2 } x & \cos 2x \\ \sin ^ { 2 } x & \cos ^ { 2 } x & \sin 2x \end{array} \right| , x \in R$ is\\
(1) $\sqrt { 7 }$\\
(2) $\frac { 3 } { 4 }$\\
(3) $\sqrt { 5 }$\\
(4) 5