Chapter 1 Introduction
The Complex Numbers idea is known in antiquity. Heron surface triangle considerations for example. The mathematicians imagined about stranged numbers i in XVI..XVII centuries then. Why strange numbers? Because i*i=-1! This is heresy after all!
The complex numbers was a heresy originally. But it helped to solve many real problems. The alternating currents emerged in XIX century for example. These currents are sinusoids. The complex numbers are very useful to calculate sinusoids–>addition, mutiplying etc. More easier than than simple trigonometry operations.
i number is known as an imaginary number as a part of the complex number. It’s used by mathematicians. But electricians use j symbol instead. Why? Because i is a current symbol for electricians.
The j as an imaginary number will be used in this article.