@tau0529 Yes, this is how one iterates the half-angles
P.S. also useful when you also want to calculate π: Change the outermost + into - will turn a cosine into sine, which approximates a small arc.
@MC_such when 本 appears isolated, it usually is a phonetic translation of the western name Ben; Actual words containing the hanzi 本 have length 2 or more.
@Doz_Math Notice that: Using the 1st row and the 2nd column, many entries are eliminated; After that, use the 4th column, then the 3rd column to eliminate more entries; What is left is, diag(1,1,2,2,{{5,4},{6,5}}), with a determinant of 4.
@shirandareka When the main verb is hidden, in this example inside "速い"((to be) fast) which is akin to other languages' adjectives, and the copula is also not appearing, the word orders suddenly collapse into one.