3. To find P.I., when Q is of the form xm In this case P.l. EDX".
Working Rule Take out the lowest degree term from F(D) and the remaining factor will be of the form [1 +f(D)] or [1-f(D)] and this factor can be taken in the numerator with a negative index which can be expanded with the help of Binomial Theorem. The expansion is to be carried upto the term D", since Dm 1xm = 0, Dm 2xm = 0 and all other higher differential coefficients of xm are zero.
Can anyone explain this.