Hi Kiran,
You can generate user defined waveforms with the 5401. So all you need to do is create the waveform first (it must be 16384 samples in size). An example for this can be found at:
http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=B53A24EA9791426CE034080020E74861&p_node=DZ52290&p_source=External
However it does depend on what you mean by a "square rooted sine signal" if you take the square root of a sine wave that varies betwwen +/- 1 then you will get parts of the waveform that are imaginary. The 5401 can only output real numbers so you will have to deal with this in your signal generation.
Regards
Jon B
Applications Engineer
NIUK & Ireland