f(x) was a four member South Korean girl group formed by SM Entertainment active from 2009 to 2016 (and a reunion in 2019 with a 3-night performance of 3 members on SMTown Live in Tokyo). The name is a play on the mathematical notation for function, with "f" signifying "flower" and "x" representing the female's double X chromosome. The group made their debut on September 1, 2009 with release of a digital single "??? (LA chA TA)". The quartet consists of ?? (Victoria), ?? (Amber), ?? (Luna), and ???? (Krystal).
Four years of hard work!This month of May we celebrated four years on the air. We continue working on the dissemination of this wonderful instrument, thank you for participating in our story!