Show-that-C-1-1-where-1-with-addition-operation-is-a-group-Help-

Question Number 191997 by Mastermind last updated on 05/May/23

Show that C = {- 1, 1, - ı, ı} where

ı = \sqrt{- 1} with addition operation is a

group .

Help!

Commented by Rasheed.Sindhi last updated on 05/May/23

a d d i t i o n i s n o t d e f i n e d i n {- 1, 1, - i, i} .

Commented by Mastermind last updated on 07/May/23

Yes!

thank you so much

Answered by AST last updated on 05/May/23

F o r a g r o u p G u n d e r o p e r a t i o n *

B y i t s p r o p e r t i e s, i f a, b \in G, t h e n a * b \in G

F o r C = {- 1, + 1, - i, i} u n d e r +, s i n c e 0 i s n o t i n

t h e s e t, (C, +) c a n n o t b e a g r o u p .

(C, \times), h o w e v e r, i s a g r o u p .

Commented by Mastermind last updated on 07/May/23

Wow!

Thank you so much, i really appreciate