De oplossingenverzameling

van   x2 ≥ 25   is 		A.   [ − 5 , 5 [
B.   ] − 5 , 5 ]
C.   [ − 5 , 5 ]
D.   \ [ − 5 , 5 ]
E.   \ ] − 5 , 5 [
F.   [ 5 , plusoneindig[
A    B    C    D    E    F 

[ 4,5-3918 - op net sinds 5.12.04-(E)-27.10.2023 ]

Translation in   E N G L I S H

The set of solutions

of   x2 ≥ 25   is 		A.   [ − 5 , 5 )
B.   ( − 5 , 5 ]
C.   [ − 5 , 5 ]
D.   \ [ − 5 , 5 ]
E.   \ ( − 5 , 5 )
F.   [ 5 , ∞ )

Oplossing - Solution

x2 ≥ 25  ⇔  x2 − 25 ≥ 0  ⇔  (x + 5)(x − 5) ≥ 0
 x    |      − 5     5     .
 x² − 25  |   +   0   −   0   +
In het schema zien we dat alleen de getallen tussen − 5 en +5 niet tot de oplossing behoren.
De oplossingenverzameling is dus  R \ ]− 5,+5[
gricha