Second order Definition and 602 Threads

Consider this sequence: 1, 2, 3, 4, 5, ... We can calculate the n'th term of the sequence by the function t(n) = n. We could define s(n), the sum to n terms, recursively as s(1) = 1 and s(n) = n + s(n-1). The time bound of this procedure is O(n), but it isn't efficient because we can...

Hello, I am having trouble understanding how to solve second order nonhomogeneous linear differential equations. I know how to solve second order homogeneous linear differential equations. But I am not following in the lecture and in the text the method of variation of parameters to solve...