3.
\((1)\)已知\(-1,{{a}_{1}},{{a}_{2}},{{a}_{3}},-9\)五个实数成等差数列,\(-1\),\(b1\),\(b2\),\(b3\),\(-9\)五个实数成等比数列,则\((a1-a3)/b2\)等于_______ .
\((2)\dfrac{\sin 160{}^\circ }{\sin 110{}^\circ }-\tan 320^{\circ}+\sqrt{3}\tan 20^{\circ}\tan 40^{\circ}=\)______.
\((3)\)已知集合\(A=\{\left. x \right|{{x}^{2}}-16 < 0\}\),\(B=\{x\left| {{x}^{2}}-4x+3 > 0 \right.\}\),则\(A∩B=\)_________.
\((4)\)如图,测量河对岸的塔高\(AB\)时,可以选与塔底在同一水平面内的两个测点\(C\)与\(D\),测得,测得\(∠BCD=75^{\circ}\),\(CD=60\),\(∠BDC=60^{\circ}\),并在点\(C\)测得塔顶\(A\)的仰角为\(60^{\circ}\),则塔高\(AB=\)________\(m\).