Integrating acceleration to find velocity

I'm not sure where I'm going wrong here. I'm given a particle's acceleration as a function of t, an initial velocity, and an initial position:

http://www.webassign.net/cgi-bin/sym...%3Ej%3C%2Fb%3E

I have to find the particle's velocity v(t) so I integrated each component and added the initial velocity:

v(t) = http://www.webassign.net/cgi-bin/pal...E%3C%2Fmath%3E

For some reason this is being marked wrong by the homework site. Can you tell me why? Am I not integrating correctly or adding the initial velocity incorrectly or something. Thanks very much for any help.