Eén van de oplossingen
van de vierkantsvergelijking
x2 − 2x − 4 = 0   is
A.   \(\boldsymbol{1 + \sqrt 5}\)
B.   \(\boldsymbol{2 + \sqrt 5}\)
C.   \(\boldsymbol{1 + 2\sqrt 5}\)
D.   \(\boldsymbol{2\sqrt 5}\)
E.   \(\boldsymbol{\sqrt 5}\)
                 

[ 3,4-6791 - op net sinds 5.1.12-(E)-18.11.2023 ]

Translation in   E N G L I S H

One of the solutions
of the equation
x2 − 2x − 4 = 0   is		 A.   \(\boldsymbol{1 + \sqrt 5}\)
B.   \(\boldsymbol{2 + \sqrt 5}\)
C.   \(\boldsymbol{1 + 2\sqrt 5}\)
D.   \(\boldsymbol{2\sqrt 5}\)
E.   \(\boldsymbol{\sqrt 5}\)

Oplossing - Solution

De discriminant van de vergelijking is
D = 4 + 16 = 20 = 4 .5
Er zijn dus twee wortels (oplossingen),
namelijk  x1,2 = 1/2 (2 ± 2) = 1 ±