Complex Number

Complex Numbers are numbers that can be written in the form of: A + Bj

Below is a graph of the imaginary plane that will help visualize what this means.

ComplexNumber ECE301Fall2008mboutin.png

A represents the real part of the complex number.

B represents the imaginary part of the complex number.

Both A and B must be real numbers.

Fact: Complex numbers are ONLY EQUAL if and only if the real coefficients are equal. Ex.

           A + Bj = C + Dj   A = C  B = D 
                 5 + 3j =/= 5 + 2j

Polar Form

In Polar Form, we use radius and angle instead of the distances x and y. r is the distance from the origin. θ is the angle in degrees.

             r*cos(θ) + j*r*sin(θ)

or written exponentially

             r*e^(j*θ)

Converting to or from Polar Form. Just remember these 3 easy equations.

                   x = r*cos(θ)
                   y = r*sin(θ)
                   r = sqrt(x^2 + y^2)

(having trouble with LaTeX. Anyone is welcome to clean these up.)

Alumni Liaison

Ph.D. 2007, working on developing cool imaging technologies for digital cameras, camera phones, and video surveillance cameras.

Buyue Zhang