Classify the following number as rational or irrational:-
(i) 2−√5
(ii) (3+√23)−√23
(iii) 2√77√7
(iv) 1√2
(v) 2π
(i) 2−√5:
Since √5 is an irrational number, 2−√5 is also an irrational number.
(ii) (3+√23)−√23:
(3+√23)−√23 =3+√23−√23=3, which is a rational number.
(iii) 2√77√7=27:
2√77√7=27, which is a rational number.
(iv) 1√2:
Since √2 is an irrational number, 1√2, which is also an irrational number.
(v) 2π:
Since π is an irrational number, 2πis also an irrational number