7.
已知向量\( \overrightarrow{a}=(\cos x,\sin x)\),\( \overrightarrow{b}=(3,- \sqrt {3})\),\(x∈[0,π]\).
\((1)\)若\( \overrightarrow{a}/\!/ \overrightarrow{b}\),求\(x\)的值;
\((2)\)记\(f(x)= \overrightarrow{a}\cdot \overrightarrow{b}\),求\(f(x)\)的最大值和最小值以及对应的\(x\)的值.