Achieving Stationarity - Question 4b

[MDBFS]

Doing some past paper questions for my Econometrics 1 class and I need some advice on how to go about doing 4b

 

[Steven G]

How can one help you with a definition?
Do you know the definition of stationary? If not, then look it up in your textbook.
Do you know the definition of a white noise process? If not, then look it up in your textbook.

 

[MDBFS]

How can one help you with a definition?
Do you know the definition of stationary? If not, then look it up in your textbook.
Do you know the definition of a white noise process? If not, then look it up in your textbook.

I was referring to 4b, recursive substitution to achieve stationarity I have no clue how to go about demonstrating it