Word · CEFR B1 · Frequency #3243
rational
/ˈræʃənəl/
noun
有理数
A rational number: a number that can be expressed as the quotient of two integers.
- 1.
A rational number: a number that can be expressed as the quotient of two integers.
有理数
- 2.
an integer or a fraction
整数或分数
整数或分数
In use
The number 0.5 is a rational because it can be expressed as 1/2.
In math class, we learned that every integer is also a rational.
He asked whether the square root of 2 is a rational.
Connections
Collocations
- rational number
- 有理数
- Every rational number can be written as a fraction of two integers.每个有理数都可以写成两个整数的分数。
- rational function
- 有理函数
- The graph of a rational function may have asymptotes.有理函数的图像可能有渐近线。
- rational expression
- 有理式
- Simplify the rational expression by canceling common factors.通过约去公因式来化简这个有理式。
- rational exponent
- 有理指数
- A rational exponent indicates a root and a power.有理指数表示根和幂。
- rational root
- 有理根
- The rational root theorem helps find polynomial roots.有理根定理有助于求多项式的根。
Synonyms
Learner notes
Memory Tip
联想ratio（比），有理数是能写成两个整数之比的数，如1/2；拼写rat-开头，记住‘比’的关系。
Context & Register
语域：formal 常见场景：数学教材、学术论文、课堂讲解 作为名词，rational 是 rational number（有理数）的简称，多用于数学或学术等正式语境；日常交流中通常说完整的 rational number。
Grammar Note
通常用于数学语境
Pronunciation & Spelling
只有 national 与 rational 真正押韵，重读元音和后面的 /ʃənəl/ 完全相同。optional、emotional、fractional、operational、constitutional 虽都以 -tional 结尾，后缀也读 /ʃənəl/，但重读元音或重音位置不同，不是真押韵。
Usage priority
Collins 词频等级为 2，建议结合例句记忆，而不是只背中文释义。
Learn the forms together
页面下方列出了常见词形变化。学习时注意它们在句子中的语法位置。
Dictionary facts from DICTIONARY_API_DEV, ECDICT, WIKTIONARY.