i^2=- 1
|i|^2= 1
Because the square of a complex number is a whole.
The square of the complex module is only for the number inside, and there is no imaginary number i.
For example, (a+bi) 2 = a 2+2 ABI+(bi) 2.
|a+bi|
=a^2+b^2
Compare the difference between the top and the bottom.