shahalam@Linux-Inspiron-5558 ~/Desktop $ sudo apt-get install nvidia-settings
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following extra packages will be installed:
  screen-resolution-extra
The following NEW packages will be installed:
  nvidia-settings screen-resolution-extra
0 upgraded, 2 newly installed, 0 to remove and 38 not upgraded.
Need to get 786 kB of archives.
After this operation, 2510 kB of additional disk space will be used.
Do you want to continue? [Y/n] Y
Get:1 http://archive.ubuntu.com/ubuntu/ trusty/main screen-resolution-extra all 0.17.1 [11.4 kB]
Get:2 http://archive.ubuntu.com/ubuntu/ trusty/main nvidia-settings amd64 331.20-0ubuntu8 [774 kB]
Fetched 786 kB in 1s (595 kB/s)          
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
	LANGUAGE = (unset),
	LC_ALL = (unset),
	LC_TIME = ""en_US.UTF-8"",
	LC_MONETARY = ""en_US.UTF-8"",
	LC_ADDRESS = ""en_US.UTF-8"",
	LC_TELEPHONE = ""en_US.UTF-8"",
	LC_NAME = ""en_US.UTF-8"",
	LC_MEASUREMENT = ""en_US.UTF-8"",
	LC_IDENTIFICATION = ""en_US.UTF-8"",
	LC_NUMERIC = ""en_US.UTF-8"",
	LC_PAPER = ""en_US.UTF-8"",
	LANG = "en_US.UTF-8"
    are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
locale: Cannot set LC_ALL to default locale: No such file or directory
Selecting previously unselected package screen-resolution-extra.
(Reading database ... 173168 files and directories currently installed.)
Preparing to unpack .../screen-resolution-extra_0.17.1_all.deb ...
Unpacking screen-resolution-extra (0.17.1) ...
Selecting previously unselected package nvidia-settings.
Preparing to unpack .../nvidia-settings_331.20-0ubuntu8_amd64.deb ...
Unpacking nvidia-settings (331.20-0ubuntu8) ...
Processing triggers for mime-support (3.54ubuntu1.1) ...
Processing triggers for desktop-file-utils (0.22-1ubuntu1) ...
Processing triggers for man-db (2.6.7.1-1ubuntu1) ...
Setting up screen-resolution-extra (0.17.1) ...
Setting up nvidia-settings (331.20-0ubuntu8) ...
shahalam@Linux-Inspiron-5558 ~/Desktop $