Definition

1. Noun (Mathematics):
   • Abstract number: A number considered without reference to any specific unit, quantity, or object. It represents a pure numerical value.
   • Imaginary number: In advanced mathematics, specifically in complex number theory, it can refer to a number that is a multiple of the imaginary unit i, where i² = -1. This meaning aligns with the French-derived term "nombre imaginaire."

Usage Examples

• Noun:
  • Trong bài toán này, chúng ta chỉ làm việc với các hư số. (In this problem, we are only working with abstract numbers.)
  • Căn bậc hai của số âm là một hư số. (The square root of a negative number is an imaginary number.)

Advanced Usage

• The term is primarily used in mathematical contexts. The specific meaning (abstract vs. imaginary) is often clarified by the surrounding mathematical discussion.

Variants and Related Words

• Số ảo: A more modern and common term for "imaginary number."
  • Số phức bao gồm phần thực và phần ảo. (A complex number consists of a real part and an imaginary part.)

Synonyms

• Abstract number: Unattached number, pure number.
• Imaginary number: (As a mathematical concept).

Notes on Usage

• "Hư số" is a specialized mathematical term. In everyday language, it is not commonly used.
• In contemporary Vietnamese mathematics education, "số ảo" is the standard term for an imaginary number, while "hư số" might be encountered in older texts or specific contexts referring to an abstract, unit-less number.

1. (toán) Abstract number