Question

Find the product of the complex number and its conjugate.
1 + 2i

Answer 1

`\overline{1+2i}=1-2i\\\\ (1+2i)(1-2i)=1+4=5`

Answer 2

so the conjugate will be 1-2i

(1+2i)(1-2i) = 1 -(2i)^2 = 1 - 4(-1) = 1+4 = 5

hope this will help you