Let R be a commutative ring and I an ideal of R, and let √I={a∈R|am∈I for some positive integer m} Show that
(i) √I is an ideal of R and I⊆√I ,
(ii) √√I=√I ,
(iii) If R is with identity and √I=R, then I=R . What is √I, when I={0}. (√I is called the radical of I).