Question

Sa se calculeze modulul numărului complex z=√2-√7i. Va rog urgent

Answer 1

$z=\sqrt 2-\sqrt 7i\\\\ \Big|z\Big|=\Big|\sqrt 2-\sqrt 7i\Big|=\sqrt{\Big(\sqrt 2\Big)^2+\Big(-\sqrt 7\Big)^2}= \sqrt{2+7}= \sqrt{9}= \boxed{3}$