7.
\((1)\)将\(a= \sqrt{5}- \sqrt{3} \),\(b=2^{0.3}\),\(c=\log _{0.3}2\)按照从小到大排列是________.
\((2)\)到球心距离为\(3\)的平面截球所得截面圆的面积为\(16π\),则该球的半径为________.
\((3)\)设函数\(f(x)=\begin{cases}{2}^{x},(x\leqslant 0), \\ {\log }_{2}x,(x > 0)\end{cases} \)函数\(y=f[f(x)]-1\)的零点个数为________.
\((4)\)设\(min\{a,b\}=\begin{cases}a,a\leqslant b, \\ b,a > b,\end{cases} \)若函数\(f(x)=min\{-{\log }_{2}x,x+ \dfrac{1}{2}\} \),则\(f(x) < \dfrac{1}{2} \)的解集为________.