一、何谓相关问题?对于一个方程组而言,如果其中至少有某一个方程可由另外的方程导出,即把某一个方程转换成较易解决的方程,则称此方程组是相关的,一般而言,对于一个问题,如果其中至少有一个已知命题或已知关系式(等式或不等式)可由其它已知命题或已知关系式逻辑推出,即把已知的条件转换为较易解决的条件,则称此问题是相关的。例如(83年高考副题)、已知数列{a_n}: First, what is the related problem? For a system of equations, if at least one of the equations can be derived from another equation, that is, converting one of the equations into a more easily solved equation, then the equation group is said to be relevant. In terms of a problem, if at least one known proposition or known relation (equation or inequality) can be derived from other known propositions or known relational logic, that is, the known condition is converted into a more easily resolved one. The conditions are said to be relevant. For example (subject to the 83rd college entrance examination), known series {a_n}: