Consider the integral equation: f(t)-8e-2019t-sen(t-u)f(u)du By applying the Laplace transform to both sides of the above equation, it is obtained that the numerator of the function F(s) is of the form (a2s2 +als+a0) (s2+1), where F(s)=L {f(t)}, then the value of a0 is equal to