diff --git a/src/8_differential_equations_2.md b/src/8_differential_equations_2.md index 681a46e32c37b762c244f1b2d0d6e1a4ee55f245..d086e5df7d383d35e22237ca1471a56b07f63607 100644 --- a/src/8_differential_equations_2.md +++ b/src/8_differential_equations_2.md @@ -1,4 +1,3 @@ -<<<<<<< HEAD --- title: Differential Equations 2 --- @@ -16,9 +15,6 @@ The lecture on differential equations consists of three parts, each with their o ## Higher order linear differential equations <iframe width="100%" height=315 src="https://www.youtube-nocookie.com/embed/ucvIiLgJ2i0?rel=0" frameborder="0" allow="accelerometer; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe> -======= -# Higher order linear differential equations ->>>>>>> df33d26965bff04a2e2724e3894837eddf801f3a In the previous lecture, we focused on first order linear differential equations as well as systems of such equations. In this lecture we switch focus to DE's @@ -217,15 +213,12 @@ $$f(x) = e^{\lambda_1 x}, \ x e^{\lambda_1 x} , \ \cdots, \ x^{m_{1}-1} e^{\lamb $$f_1(x)=e^{0 x} = 1, \ f_{2}(x) = x e^{0 x} = x. $$ -<<<<<<< HEAD + ## Partial differential equations: Separation of variables <iframe width="100%" height=315 src="https://www.youtube-nocookie.com/embed/I4ghpYsFLFY?rel=0" frameborder="0" allow="accelerometer; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe> ### Definitions and examples -======= -# Partial differential equations ->>>>>>> df33d26965bff04a2e2724e3894837eddf801f3a A partial differential equation (PDE) is an equation involving a function of two or more indepenedent variables and derivatives of said function. These equations @@ -357,11 +350,7 @@ problem, a boundary value problem does not always have a solution. For example, in the figure below, regardless of the initial slope, the curves never reach $0$ when $x=L$. -<<<<<<< HEAD  -======= -<img src="figures/DE2_1.png" width="650"> ->>>>>>> df33d26965bff04a2e2724e3894837eddf801f3a For boundary value problems like this, there are only solutions for particular eigenvalues $\lambda$. Coming back to the example, it turns out that solutions @@ -414,13 +403,11 @@ Notice that there is one solution $\psi_{n}(x,t)$ for each natural number $n$. These are still very special solutions. We will begin discussing next how to obtain the general solution in our example. -<<<<<<< HEAD + ## Self-adjoint differential operators <iframe width="100%" height=315 src="https://www.youtube-nocookie.com/embed/p4MHW0yMMvY?rel=0" frameborder="0" allow="accelerometer; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe> -======= -## Self-adjoint differential equations: Connection to Hilbert spaces! ## ->>>>>>> df33d26965bff04a2e2724e3894837eddf801f3a + As we hinted was possible earlier, let us re-write the previous equation by defining a linear operator, $L$, acting on the space of functions which satisfy