I almost got the answer but I'm negative off uhh I put my steps down their if you could Pleaassse look at them but uhh I'm new to integrals so I think they will be difficult to follow cuz I don't really know what I'm doing.
okay so I have t^2 e^u
u = -t^3
-3t^2 dt = du
t^2 dt= (-1/3)du
so then I have: (-1/3)du *e^u
then I did the integral of e^u (leaving behind the -1/3 from the du)
(-1/3) ((e^(-t^3))/(-1))
The answer in my text is (-1/3)((e^(-t^3))