6.
已知向量\(\overrightarrow{a}\),\(\overrightarrow{b}\)满足\(|\overrightarrow{a}|=\sqrt{3}\),\(|\overrightarrow{b}|=2\),\((\overrightarrow{a}-\overrightarrow{b})\bot \overrightarrow{a}\).
\((1)\)求向量\(\overrightarrow{a}\)与\(\overrightarrow{b}\)的夹角及向量\(\overrightarrow{b}\)在向量\(\overrightarrow{a}\)方向上的投影;
\((2)\)求\(|2\overrightarrow{a}-\overrightarrow{b}|\)的值;
\((3)\)若向量\(\overrightarrow{c}=\overrightarrow{a}+2\overrightarrow{b}\),\(\overrightarrow{d}=m\overrightarrow{a}-2\overrightarrow{b}\),\(\overrightarrow{c}\parallel \overrightarrow{d}\),求\(m\)的值.