Complex number

A complex number is a number that can be expressed in the form \( a + bi \), where: - \( a \) and \( b \) are real numbers, - \( i \) is the imaginary unit, defined as \( i = \sqrt{-1} \). In this representation: - \( a \) is called the **real part** of the complex number, - \( b \) is called the **imaginary part** of the complex number.