Magnitude of complex number

greennblue
Wed, 30 May 2007 12:10:38 +0000

The complex number a + bi is represented in the complex plane as the point (a,b). The magnitude is the distance of this point from the origin, namely, sqrt(a^2 + b^2). So if for example you have the complex number 3 - 4i, its magnitude is sqrt(9 + 16) = 5.