While going through RFC1321, I came across the following paragraph: This step uses a 64-element table T[1 ... 64] constructed from the sine function. Let T[i] denote the i-th element of the table, which is equal to the integer part of 4294967296 times abs(sin(i)), where i is in radians. The elements of the table are given in the appendix. From what I understood from paragraph, it means T[i] = Integer_part(4294967296 times abs(sin(i))) We know the following is true for all x: 0 <= sin(x) <= 1 Since i is an integer, abs(sin(i)) may very well be 0 for all values of i. That means table will contain all zero values ( 4294967296 times 0 is 0). In the implementation, this is not true. Why is this so? Appendix contains just the raw values after calculation. It does not show how it is derived from the sine function.