Welcome to Week 3 of Differential Equations for Engineers. In this week, we'll learn about linear and 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 g of t, where g of t is called the inhomogeneous term. Inhomogeneous terms typically represent forces that might be applied to an engineering system. We will focus on the inhomogeneous second-order ODE with constant coefficients. Inhomogeneous terms, we will consider our exponential functions, sine or cosine functions, and polynomials. We'll also learn about resonance and damped resonance. Physically resonance occurs, when the frequency of the force matches the natural frequency of the system. Mathematically resonance happens when the inhomogeneous term is a solution of the the homogeneous equation. Applications we'll learn about are the resistor inductor capacitor or RLC circuit, a mass oscillating on a spring, and a pendulum. Please join me in this third week of Differential Equations for Engineers.