Respuesta :

[tex]a,b\in\mathbb{R}\\ z=a+bi\\ \overline{z}=a-bi\\\\ z\cdot\overline{z}=(a+bi)(a-bi)=a^2+b^2[/tex]

If [tex]a,b\in\mathbb{R}[/tex] then also [tex](a^2+b^2)\in\mathbb{R}[/tex], so it's true.
HI THERE !!

yes, this is true, the product of a complex number and its conjugate is its real number!!


have a good day :)