F (x) (f. x.) is a Korea's dance-pop music group. F (x) is expanded to Victoria, amber, Luna, Sully, consisting of a 5-Member girl group is a multinational with Crystal. F (x) is the functional __EXPRESSION__ of mathematics, as a result, changing the formula, depending on the value of x as members of diverse talents and charms based on wanting to spread the colorful activities.Also, the "f", "x" is the female flower XX chromosomes X, Ta and ' women of the reminiscent of the flower ' symbol, and Asia's best pop dance group aims to grow.[1] on September 1, 2009, x is a digital single-〈manufacture (LA chA TA) od 〉 debut, at the time known as the "second girls ' generation", and got a good response. In the same year on November 4, the single "Chu-law firm", was released on the activity.May 3, 2010, the first EP album by the NU--Oh yes beep, we've been released from an unusual Electronica sound by critics and received positive reviews. 2011 's first Studio album on April 20, and the release and activity of Pinocchio for the first time, got a great commercial success, such as rising above 1.