I'm not sure if I did this correctly.
s(t)= √(t^2 + 2t)
s'(t)= (t + 1)/[√(t^2 + 2t)]
Here's where I have trouble:
s''(t)= (t^2 + 2t)^(-1/2) (t + 1)
= (-1/2)(t^2 + 2t)^(-3/2) (t + 1) + (t^2 + 2t)^(-1/2) (1)
= 1/[√(t^2 + 2t)] - (t+1)/[2(t^2 + 2t)^(3/2)]
Is this the correct answer?