Cot x is 1/tan x or cos x / sin x or +- sqrt cosec^2 x -1.
Original Cast Recording. Arista, 1973. Includes original hit song Day by Day sung by Robin Lamont. Sung by the original cast members David Haskell, Peggy Gordon, Robin Lamont, Gilmer McCormick, Sonia Manzano, Jeffrey Mylett, Stephen Nathan, Herbie Braha, Joanne Jonas, and Lamar Alford.
One Day at a Time, which aired from December 1975 to May 1984, starred Bonnie Franklin as a divorced mom raising two teenage girls (Mackenzie Phillips, Valerie Bertinelli) in an apartment in Indianapolis.