Consider the MA(2) model invertibility conditions and (iii) Pick choices of b1 and b2 that violate each condition, but only one condition at a time. In each case, show b(B) = 0 has one or more...

Consider the MA(2) model

invertibility conditions

and (iii)

Pick choices of b1 and b2 that violate each condition, but only one condition at a time. In each case, show b(B) = 0 has one or more roots inside the unit circle. Since b(B) = 0 is a quadratic, it should be possible to do this easily.