Listen NCERT Audio Books to boost your productivity and retention power by 2X.
Let A = (1, -1, i, -i) be the set of four 4th roots of unity. Prepare the composition table for multiplication on A and show that
(i) A is closed for multiplication,
(ii) multiplication is associative on A,
(iii) multiplication is commutative on A,
(iv) 1 is the multiplicative identity,
(v) every element in A has its multiplicative inverse.