In the complex numbers, where i^2 = -1

In the complex numbers, where i2 = -1,

1/(1 + i) · (1 - i)/(1 - i) = ?

  1. i - 1
  2. 1 + i
  3. 1 - i
  4. (1 - i)/2
  5. (1 + i)/2

Answer

The correct answer is D.

To find an equivalent expression for 1/(1 + i) · (1 - i)/(1 - i), multiply and get

= 1(1 - i) / [(1 + i)(1 -  i)]

= (1 - i) / (1 - i2)

= (1 - i) / 2