10.
已知向量\( \overrightarrow{a}=(\cos \dfrac {3x}{2},\sin \dfrac {3x}{2})\),\( \overrightarrow{b}=(\cos \dfrac {x}{2},-\sin \dfrac {x}{2})\),函数\(f(x)= \overrightarrow{a}⋅ \overrightarrow{b}-m| \overrightarrow{a}+ \overrightarrow{b}|+1\),\(x∈[- \dfrac {π}{3}, \dfrac {π}{4}]\),\(m∈R\).
\((1)\)当\(m=0\)时,求\(f( \dfrac {π}{6})\)的值;
\((2)\)若\(f(x)\)的最小值为\(-1\),求实数\(m\)的值;
\((3)\)是否存在实数\(m\),使函数\(g(x)=f(x)+ \dfrac {24}{49}m^{2}\),\(x∈[- \dfrac {π}{3}, \dfrac {π}{4}]\)有四个不同的零点?若存在,求出\(m\)的取值范围;若不存在,说明理由.