Quote by Daverz
I think you can do it if you start with the special cases
[tex] v_{a}t_{aa} = 0 [/tex]
[tex] 2 v_{a}t_{ab} + v_{b}t_{aa}= 0 [/tex]

I don't know
You're first equation only implies that either v_a or t_aa is 0 for a given a. Using the first one with the second one doesn't really imply anything because both v_a and t_aa could be 0 so then there would be no restrictions on t_ab or v_b.