phi(b)y what is the function of phi in a pre-whitening time series? which function is used in the pre-whitening approach? what is pre whitening how to calculate pre whitening epsilon is a time series how to use epsilon to calculate arc what is the formula for calculating the pre-whitening how to determine the pre-whitening value of the r(2) time series when do i use phi and phi_2 in the equation what is phi(b) used for in a pre whitening model ir(2) time series calculate pre-whitening when to use the pre whitening i want to use prewhitening equation if you use pre whitenning approach to the equation y you can calculate the how to find pre whitening of time series when do you use pre whitenning formula how to estimate pre whitenning of ar(2) what is the physic model for r(a) of time series