Q
quynhan92


[FONT=.VnTime](tanx + 1/4 cotx)^n = cos^nx + sin^nx[/FONT]
[FONT=.VnTime]cac ban lam thu xem nha![/FONT]
[FONT=.VnTime]cac ban lam thu xem nha![/FONT]
Last edited by a moderator: