在正三棱柱\(ABC-A_{1}B_{1}C_{1}\)中,已知\(AB=1\),\(AA_{1}=2\),\(E\),\(F\),\(G\)分别是\(AA_{1}\),\(AC\)和\(A_{1}C_{1}\)的中点\(.\)以\(\{ \overrightarrow{FA}, \overrightarrow{FB}, \overrightarrow{FG}\}\)为正交基底,建立如图所示的空间直角坐标系\(F-xyz\).
\((1)\)求异面直线\(AC\)与\(BE\)所成角的余弦值;
\((2)\)求二面角\(F-BC_{1}-C\)的余弦值.