10.
函数\(f\left( x \right)=\dfrac{{{\log }_{3}}\left( x+1 \right)}{x+1}\left( x > 0 \right)\)的图象上有一点列\({{P}_{n}}\left( {{x}_{n}},{{y}_{n}} \right)(n{∈}N_{{+}})\),点\({{P}_{n}}\)在\(x\)轴上的射影是\({{Q}_{n}}\left( {{x}_{n}},0 \right)\),且\({{x}_{n}}=3{{x}_{n-1}}+2\)\((\)\(n{\geqslant }2\)且\(n{∈}N\)\()\),\({{x}_{1}}=2\).
\((1)\)求出数列\(\left\{ {{x}_{n}} \right\}\)的通项公式;
\((2)\)对任意的正整数\(n\),当\(m{∈}{[}{-}1{,}1{]}\)时,不等式\(3{{t}^{2}}-6mt+\dfrac{1}{3} > {{y}_{n}}\)恒成立,求实数\(t\)的取值范围;
\((3)\)设四边形\({{P}_{n}}{{Q}_{n}}{{Q}_{n+1}}{{P}_{n+1}}\)的面积是\({{S}_{n}}\),求证:\(\dfrac{1}{S_{1}}{+}\dfrac{1}{{2S}_{2}}{+}{…}{+}\dfrac{1}{{nS}_{n}}{ < }\dfrac{5}{4}\).