Home /
Expert Answers /
Other Math /
6-let-a-and-k-be-as-in-5-prove-that-i-a-2-1-mod-2-if-and-only-if-a-1-mod-2-ii-a-pa656

(6) Let a and k be as in (5). Prove that (i) a 2 ? 1 mod 2 if, and only if, a ? 1 mod 2; (ii) a 2 ? 1 mod 22 if , and only if, a ? ±1 mod 22 ; (iii) For k ? 3 we have a 2 ? 1 mod 2k if, and only if, a ? ±1 mod 2k or a ? 2 k?1±1 mod 2k .