How to use genetic algorithm in getting the minima for a differential equation?

Hello I want to solve an equation of motion and get the best solution compared to a defined response using the genetic algorithm. As I noticed the objective function is a simple function of x, whereas in my case I want to vary, let us say, three variables mass, stiffness, and damping coefficient, according to the equation:

[Alaa Hameed]

The equation showed in the figure attached