Answer the following questions related to special product identities of binomials.
a. (i) State the general identity for (x+y)3.
b. (ii) Describe how the identity for (x−y)3 differs from that of (x+y)3 with special reference to the signs of the middle terms.
c. (iii) Verify your explanation in part (ii) by substituting x=2 and y=1 in both identities and simplifying the numerical results.