The term “Complex Number” always seems to scare algebra students – BUT – complex numbers are complex in name only. They are NOT really complex. Once you get the concept, they are simple to use and work with.
A complex number always has two parts. One is real and the other imaginary. When combined, the total quantity is called complex.
The imaginary part is always accompanied by the term i or sometimes j. Engineers often will use j because i can also refer to [katex]y=x^{2}[/katex] electrical current. The real part of a complex number just looks like a normal number. NOTE: The real and imaginary parts CANNOT be combined but rather must always remain separate.
- x = 3 + 2i ‘3’ is real, ‘2’ is imaginary, and ‘x’ is complex. [katex]y=x^{2}[/katex]
- y = z – 7i ‘z’ is real, ‘-7’ is imaginary, and ‘y’ is complex
- z = a + bi ‘a’ is real, ‘b’ is imaginary, and ‘z’ is complex