For the harmonic oscillator in 1-D we get the 2nd time derivative of the x Heisenberg operator = -ω2 x. When that is integrated it gives xH (t) = Acos(ω t) +Bsin (ω t) where A and B are time independent operators. My question is why are the constants A and B incorporated into the terms as a multiplicative factor instead of being additive constants ? And what would happen if the term to be integrated already had an operator in it. you wouldn't know whether to place the multiplicative constant before or after the other operator ?