Square Root Day September 9, 1981 (9/9/81). Gordon remains the holiday's publicist, sending news releases to world media outlets. Gordon's daughter set up a Facebook group where people can share how they were celebrating the day. One suggested way of celebrating the holiday is by eating square radishes, or other root vegetables cut into shapes with square cross sections (thus creating a "square root"). Square Root Day occurs on the following dates each century: The number of years between consecutive Square Root Days in a century are consecutive odd numbers: 3, 5, 7, 9, 11, 13, 15, 17. This illustrates the fact that
Square root of a matrix but if the process converges, the matrix formula_26 converges quadratically to a square root , while formula_27 converges to its inverse, . Yet another iterative method is obtained by taking the well-known formula of the Babylonian method for computing the square root of a real number, and applying it to matrices. Let "X" = "I", where "I" is the identity matrix. The iteration is defined by Again, convergence is not guaranteed, but if the process converges, the matrix formula_29 converges quadratically to a square root "A". Compared to Denman–Beavers iteration, an advantage of the Babylonian method is that only one