phức số

Definition
  1. Noun:
    • Complex number: In mathematics, a number that can be expressed in the form a + bi, where a and b are real numbers, and i is the imaginary unit satisfying i² = -1.
    • Non-decimal number: A number whose calculation or representation does not follow the base-10 (decimal) system, such as time expressed in hours and minutes (e.g., 1 hour 30 minutes).
Usage Examples

  • Noun (Mathematical):

    • Trong toán học, 'phức số' là một khái niệm cơ bản. (In mathematics, 'complex number' is a fundamental concept.)
    • Phương trình này yêu cầu phải sử dụng phức số để giải. (This equation requires the use of complex numbers to solve.)

  • Noun (Non-decimal):

    • Khi tính thời gian, chúng ta thường dùng phức số như 2 giờ 15 phút. (When calculating time, we often use non-decimal numbers like 2 hours 15 minutes.)
Advanced Usage
  • "Số phức": This is the more standard and modern Vietnamese term specifically for the mathematical "complex number." "Phức số" is an older or less common variant.
    • Số phức có phần thực và phần ảo. (A complex number has a real part and an imaginary part.)
Variants and Related Words
  • Số phức (n): Complex number. The preferred modern term in mathematics.
  • Số ảo (n): Imaginary number (specifically the component of a complex number).
  • Số thực (n): Real number.
Synonyms
  • Complex number (for the mathematical meaning).
  • Compound number (for the non-decimal meaning, e.g., in time or angle measurement).
Notes on Usage
  • The term "phức số" is now considered somewhat archaic or specialized. In contemporary academic and technical contexts, especially in mathematics, "số phức" is universally used to mean "complex number."
  • Its secondary meaning describing non-decimal systems (like time) is derived from the literal interpretation of "phức" (complex) and "số" (number), indicating a number composed of multiple units. This usage is descriptive rather than a formal mathematical term.