in case of IRP: So x ( 1 + Rdcx60/360)/(1 + Rfg x 60/360) = S(E)
While Swap valuation FP = So + F/(1 + Rf) ^60/360
I noticed that when dealing with LIBOR , to adjust the rate for the period , they just use the annual rate multiplied with the ration of the year e.g 60/360. but in case of Swap, they don’t adjust the risk free this way but it is raised to the power ^60/360.
What is the rationale behind this ?
thank you so much