Question

calcule o complexo  : $x2 -8x+17=0$

Answer 1

Olá Bia, ^^

lembre-se que √-1 = i:

$x^2-8x+17=0\\\\ \Delta=(-8)^2-4\cdot1\cdot17\\ \Delta=64-68\\ \Delta=-4\\\\ x= \dfrac{-(-8)\pm \sqrt{-4} }{2\cdot1}= \dfrac{8\pm \sqrt{4}\cdot \sqrt{-1} }{2}= \dfrac{8\pm2\cdot i}{2}= \dfrac{8\pm2i}{2}=4\pm i\\\\\\ \large\boxed{\boxed{S=\{4+i,~4-i\}}}.\\.$

Tenha ótimos estudos =))