\((1)\)已知点\(A(0,1),B(3,2)\),向量\(\overrightarrow{AC}=(-4,-3)\),则向量\(\overrightarrow{BC}=\)__________.
\((2)\)已知直线\(l:\dfrac{x}{a}+\dfrac{y}{b}=1(a > 0,b > 0)\)经过点\((3,2)\),则\(a+b\)的最小值为______.
\((3)\)在封闭的直三棱柱\(ABC-A_{1}B_{1}C_{1}\)内有一个体积为\(V\)的球\(.\)若\(AB⊥BC\),\(AB=6\),\(BC=8\),\(AA\)\({\,\!}_{1}\)\(=3\),则\(V\)的最大值是__________.
\((4)\)已知函数\(f(x)=\begin{cases}x\ln (1+x)+{x}^{2},x\geqslant 0 \\ -x\ln (1-x)+{x}^{2},x < 0\end{cases} \),若\(f(-a)+f(a)\leqslant 2f(1) \),则实数\(a\)的取值范围是__________.