The imaginary unit "i" is the square root of -1:
i = √-1
An imaginary number (#) is a product of a real # and the imaginary unit.
h = b*i where h is an imaginary # and b is a real # [a # you can find on the (real) # line]
A complex # is a sum of a real # and an imaginary #:
z = a +ib Where z is a complex #, and a and b are real #'s.
When you add together two complex #'s, you add real parts w/ real parts, and imaginary parts w/ imaginary parts, ex:
z1 = 5 +3i and z2 = 7 - 2i
z1 + z2 = 5 +3i + 7 - 2i = 12 + i
When you multiply them, you do the same as you would do w/ real #'s, except that you have to remember that i2 = -1:
z1 * z2 = (5 +3i)(7 - 2i) = 35 - 10i + 21i -6i2 = 35 +11i - (-6) = 41 +11i