题型:填空题 题类:月考试卷 难易度:较难
\((1)\) 在几何体\(①\)圆锥;\(②\)正方体;\(③\)圆柱;\(④\)球;\(⑤\)正四面体中,三视图可能完全一样的是________.
\((2)\)若数列\(\{a_{n}\}\)满足\({a}_{1}=2,{a}_{n}=1- \dfrac{1}{{a}_{n-1}} \),则\(a_{2017}=\)___.
\((3)\) 若\(x,y\)满足\(\begin{cases} & x\leqslant 3, \\ & x+y\geqslant 2 \\ & y\leqslant x, \end{cases}\),则\(x+2y\)的最大值为___________.
\((4)\triangle ABC\)的内角\(A\),\(B\),\(C\)的对边分别为\(a\),\(b\),\(c\),若\(\cos A=\dfrac{4}{5} \),\(\cos C=\dfrac{5}{13} \),\(a=1\),则\(b=\)____