Why not try? I won't write it for you, as the entire problem is to make you think. I'll give you one hint, and I will hope nobody does the rest of your homework for you.
A vector is a palindrome if the first and last elements are the same, AND...
.... what else? That is, what information do you need about the rest of the vector? Is there some way you can treat this in a recursive way?
This is your homework, not ours, remember.