f(x) (Korean: 에프엑스) is a five member South Korean girl group formed by SM Entertainment in 2009. The name is a play on the mathematical notation for function, and when input with different 'x', there can be many different outcomes. The f stands for flower and the x represents the female's double x chromosome. f(x) strives to be the kind of girl group that can change and adapt to many situations. The group members have also been nicknamed "function girls". The group made their debut on September 1, 2009 with release of a digital single "La Cha Ta" (stylized as "LA chA TA"). The quintet consists of Victoria, Amber, Luna, Sulli and Krystal.

Members:
빅토리아 - Victoria - February 2, 1987
엠버 - AmberAmber - September 18, 1992
루나 - Luna - August 12, 1993
설리 - Sulli - March 29, 1994
크리스탈 - Krystal - October 24, 1994

Discography:
Studio albums:
Pinocchio (2011)

Repackaged albums:
Hot Summer (2011)

Extended plays:
Nu ABO (2010)
Electric Shock (2012)

Singles:
La Cha Ta (2009)
"Chu~(2009)
Nu ABO (2010)
Pinocchio (Danger) (2011)
Hot Summer (2011)

Promotional singles:
Chocolate Love (2009)
Lollipop (2010)
Mr Boogie (2010)

Source
La Cha Ta:


Nu ABO:


Pinocchio (Danger):


Hot Summer:
so the one in black in the top pic, that's a chick? if so they should call on that chick next time there's a drama about a girl posing as a guy, b/c that is very convincing.
WHOOO f(x) thread !! Amber is my love ;__; ♥
I only like a couple of their songs, so I don't consider myself a fan. But I ♥ Amber.
f(x) are in my TOP 5 girl groups
Woah, we didn't have an f(x) thread before? Anyway, f(x) is gonna come out with their new mini-album 'Electric Shock' on iTunes on 10th June, and in stores on 13th June. The teaser photos are definitely intriguing, and although I'm eerily reminded of SHINee's Sherlock's teaser pics, I'm still pretty darn excited ^^ On a side note, I was hoping it would be an album and not a mini album though :o


Meh, it's a little worrisome... especially the last pic.
Sounds quite good :O but the ending reminded me a lot of SHINee's Lucifer
Omg, I was skeptical but their new album is AWESOME. Their best yet. My favourite is Electric Shock and Let's Try.

Also, MV teaser:



Even though it looks like another box MV, it looks really cool.
에프엑스_Electric Shock_Music Video
I'm not really into f(x), none of there songs have really appealed to me beyond that I like Electric Shock.
Just watched the MV and listened the song ~ DAMN i love the song ! And I love their outfits and contact lenses ~~
I am really impressed with f(x)! I've really like the majority of their songs and I think Electric Shock is great, but I just don't like that part of the chorus. when they say "nananananana". That is mildly annoying.