1) Given those functions, f(t) and g(t) let's find the composite function, for (f(g(0)) or (f •g)(0)
2) Let's pick the function f(t)
f(t) = 2t-3
And plug into that g(t), like this
f(g(t))= 2(t³ +t) -3
3) Finally, let's plug the value 0 into that composite function:
f(g(t))= 2(t³ +t) -3
f(g(0))= 2(0³ +0) -3 ⇒f(g(0))= 2(0) +3
f(g(0))= 3
(f •g)(0)=3