1. The problem statement, all variables and given/known data Solve the first order difference equation. 2. Relevant equations x[n] - x[n-1] = n(n+1)/2 x = 1 3. The attempt at a solution Homogenous solution: Characteristic equation: r - 1 = 0 <=> r = 1 => yhn = C * 1^n = C Particular solution: ypn = ? I'm supposed to do some intelligent guess here. n(n+1)/2 is a polynomial of degree 2 and dosnt exist in yhn so i should be something like An(n+1) or An^2+Bn but Ican't get anything to work.