数列不等式是高考数学的热点,且常常出现在压轴题中,扮演着控制整张试卷区分度的角色。数列不等式的证明常利用比较法、放缩法等常用的方法。一、比较法例1已知数列{a_n}等差数列,且a_3=7,3a_1+a_2=24,S_a为前n项和。(I)求数列{a_n}的通项公式;(Ⅱ)若p,q为正整数,且p≠q,求证S_(p+q)< The numerical inequality is a hot spot in college entrance examination mathematics, and often appears in the finale, which plays the role of controlling the degree of differentiation of the whole paper. The proofs of numerical inequalities often use comparative methods, scaling methods and other commonly used methods. First, comparative law 1 known series {a_n} equal difference sequence, and a_3 = 7,3a_1 + a_2 = 24, S_a for the first n terms and. (I) the general formula of the {a_n} sequence; (Ⅱ) if p and q are positive integers and p ≠ q, verify that S_ (p + q)