If f(n)=n2f(n) = n^2f(n)=n2, what is the trial form of the particular solution pnp_npn for an=5an−1−6an−2+n2a_n = 5a_{n-1} - 6a_{n-2} + n^2an=5an−1−6an−2+n2?
An2+Bn+CAn^2 + Bn + CAn2+Bn+C
An3+Bn2+CnAn^3 + Bn^2 + CnAn3+Bn2+Cn
An2An^2An2
An2+BAn^2 + BAn2+B