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 second order nonhomogeneous linear differential equations. For one's information I am using the text Calculus, 4th edition by James Stewart and the chapter is 18 and the section is 2. The page is 1170 for anyone familiar with this text. Any help with this method would be appreciated. Thankyou.