f(x) (Korean: 에프엑스; pronounced /ɛfːˈɛks/) is a girl group that formed in Seoul, South Korea in 2009 by SM Entertainment. 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 quintet consists of leader Victoria, Krystal, Sulli, Luna, and Amber.
Krystal was first spotted by SM Entertainment in 2000, which earned her a small role in a short segment of Shinhwa's "Wedding March" music video. Six years later, SM recruited Luna after seeing her performing on a television program.In September 2007,SM discovered Victoria performing in a dance competition in Beijing, China, which brought her to South Korea for a modeling and acting career. A month later, Amber was casted from an audition in Orange County, California.
While Krystal was the first member to make a media appearance, having appeared briefly in a Lotte commercial in 2002, Sulli was the first member to make a debut, officially debuting as a child actress in September 2005 as the role of young Princess Sun-hwa in the SBS television drama, The Ballad of Seodong.Victoria was the second; she made her first appearance as a model for SPRIS with Korean actor-singer Lee Jun-ki in early 2008 with announced modeling activities in the future.Krystal began training for f(x) in 2006 along with Sulli and Luna.Amber joined them in early 2008, with Victoria the last to join the group, in the later months of 2008.
Pre-debut
SM released a teaser preview of the group via YouTube on August 24, 2009, introducing them as "Asia's Pop Dance Group."For five days, SM individually released information through news portals and posted pictures of each member on SM Town's official website, starting with Sulli on August 26.Taiwanese-American member Amber was revealed on August 27Krystal on August 28, Luna on August 29,and Victoria last on August 30.
2009: Debut and first album
The group's first single "LA chA TA" was digitally released on September 1, followed by a 40-second teaser of their music video uploaded to YouTube.f(x) had their first performance at a showcase specifically assigned for their debut at the Samseong-dong Fashion Center on September 2, in which the event was hosted by Leeteuk and Sunny.The full music video of "LA chA TA" debuted at the showcase, and was released online the next day. The group debuted their first broadcasted performance of "LA chA TA" on MBC's music show Show! Music Core on September 5.
On October 7, f(x), along with label-mate Girls' Generation released a digital single named "Chocolate Love" for the 4th edition of the Blacklabel series LG CYON phone, "Chocolate". f(x) sang the "Electronic Pop Ver." of the song while Girls' Generation sang the "Retro Pop Ver."
f(x)'s first Album Single, "Chu~♡", was released on November 9, consisting of 3 songs.
Also, f(x) members Luna and Krystal contributed to the soundtrack of television series Invincible Lee Pyung Kang with a duet "Difficult and Easy".
2010: Overseas
The group collaborated with Chinese boy band M.I.C. for a Chinese song "Lollipop" to promote the LG CYON phone.
Krystal, Luna and Amber also participated in the KBS Drama "God of Study" OST Part 2, with their song "Spread its Wings", which was released in late January.
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F(x)-Chu
F(x)-Lachata
F(x)-Chocholate love
F(x) ft. M.I.C-Lollipop