7.
\((1)\)已知命题\(p\):\(∀\)\(n\)\(∈N\),\(n\)\({\,\!}^{2} < 2\)\({\,\!}^{n}\),则\(¬\)\(p\)为______.
\((2)\)\(\cos \)\(75^{\circ}\)\(\cos \)\(15^{\circ}-\)\(\sin \)\(255^{\circ}\)\(\sin \)\(165^{\circ}\)的值是 .
\((3)\)已知向量\( \overset{→}{m}=(1,2) \),\( \overset{→}{n}=(2,3) \),则\( \overset{→}{m} \)在\( \overset{→}{n} \)方向上的投影为 .
\((4)\)函数\(f\)\((\)\(x\)\()=2\)\(x\)\({\,\!}^{2}-\)\(\ln x\)的单调减区间是______.