Inequalities: Key Concepts for IB and AQA Mathematics | 不等式：IB 与 AQA 数学核心考点精讲

📚 Inequalities: Key Concepts for IB and AQA Mathematics | 不等式：IB 与 AQA 数学核心考点精讲

Inequalities are a cornerstone of algebra, bridging numerical comparisons with graphical representations. In IB and AQA mathematics curricula, you will tackle a variety of inequality types: linear, quadratic, polynomial, rational and those involving absolute values. Understanding how to solve them and represent solutions accurately is crucial for higher-level topics such as calculus, linear programming, and statistical constraints.

不等式是代数的基石，架起了数值比较与图形表示之间的桥梁。在IB和AQA数学课程中，你将处理各种类型的不等式：线性、二次、多项式、有理以及含绝对值的不等式。准确求解并正确表示解集对于微积分、线性规划和统计约束等高阶主题至关重要。

1. What is an Inequality? | 不等式是什么？

An inequality expresses a relationship where two expressions are not necessarily equal. The symbols used are < (less than), > (greater than), ≤ (less than or equal to) and ≥ (greater than or equal to). Unlike equations, the solution is usually an interval or union of intervals. We denote solutions using set-builder notation {x | condition} or interval notation such as (a, b), [a, b], (a, b] or using infinity ∞.

不等式表示两个表达式不一定相等的关系。使用的符号有 <（小于）、>（大于）、≤（小于等于）和 ≥（大于等于）。与方程不同，解通常是一个区间或区间的并集。我们用集合构建符号 {x | 条件} 或区间表示法如 (a, b)、[a, b]、(a, b] 或使用无穷大 ∞ 来表示解。