A fly travels up and down with a position function (in centimeters) of x(t) = Z 4t sin(t) t 2 f(r) dr where f(r) is

A fly travels up and down with a position function (in centimeters) of x(t) = Z 4t sin(πt) t 2 f(r) dr where f(r) is a continuous function. What is the velocity of the fly at t = 2 given that f(x) is a continuous function satisfying f(n) = n 2 − 3n + 1 for every integer n?