factorial

factorial — 名詞

1. A value that you calculate by taking a given whole number and multiplying it by

1.名詞B2
釋義

階乘

從1乘到該數的乘積

A value that you calculate by taking a given whole number and multiplying it by every smaller whole number down to 1. For example, the factorial of 5 (written as 5!) is 5 × 4 × 3 × 2 × 1 = 120.

例句

Tariro learned from her textbook that 5 factorial, written as 5!, equals one hundred and twenty.

Tariro 從課本中學到 5 的階乘寫成 5!,等於 120。

5! notation: factorial written as number followed by exclamation mark

The computer science students wrote a short program to calculate the factorial of any number typed into the console.

電腦科學課的學生寫了一個簡短程式,用來計算輸入的任何數字的階乘。

factorial + of + number in computing context

同義詞
  • product

    a more general term for the result of any multiplication; not specific to the 1-to-n operation

文法句型

factorial + of + number

用法筆記

In mathematical writing, the factorial of a number n is written as n! (read as 'n factorial'). The value grows very quickly — the factorial of 20 is already over 2.4 quintillion.

常見錯誤

The factorial of 5 is 5 + 4 + 3 + 2 + 1 = 15.
The factorial of 5 is 5 × 4 × 3 × 2 × 1 = 120.
💡Factorial uses multiplication, not addition.
A factorial is a number that divides another number evenly.
A factorial is a value you get by multiplying a whole number by every smaller whole number down to 1.
💡This confuses factor with factorial.

factorial — 形容詞