Welcome to week 2 of differential equations for engineers. In this week, we'll learn about linear homogeneous differential equations. The second-order ode has the form d squared x dt squared plus p of t dx dt plus q of t x equals 0. It's important that the functions p and q do not depend on x or any of its derivatives. These all these commonly arise from engineering systems without any external forces. I'll begin by generalizing the oil and numerical method to these ode's and then develop two theoretical ideas. The principle of superposition and the Wronskian. We'll then tackle the second-order homogeneous ode with constant coefficients. This ode takes the form a, d squared x dt squared plus b dx dt plus cx equals 0 where a, b, and c are constants. We'll need to discuss both the exponential and the sine and cosine solutions of this equation. Please join me in the second week of differential equations for engineers.