Welcome back. Integration by parts is a very useful technique that usually shows up in introductory calculus courses. It allows us to efficiently integrate the product of two functions by transforming a difficult integral into an easier one. When working with a single variable, the integration by parts formula appears as follows: ∫[a,b] g(x) (df/dx) dx = g(b)f(b) - g(a)f(a) … [Read more...] about Higher Dimensional Integration By Parts and Some Results on Harmonic Functions
Separation of Variables and the Method of Characteristics: Two of the Most Useful Ways to Solve Partial Differential Equations
Welcome back. I hope all of my readers are having an excellent start to the new semester. Over the last couple of months, we have discussed partial differential equations (PDEs) in some depth, which I hope has been interesting and at least somewhat enjoyable. Today, we will explore two of the most powerful and commonly used methods of solving PDEs: separation of variables and … [Read more...] about Separation of Variables and the Method of Characteristics: Two of the Most Useful Ways to Solve Partial Differential Equations
The Lebesgue Integral: A Newer and More Flexible Alternative to the Riemann Integral
Welcome back. This week, I am excited to delve into the Lebesgue integral, which is a more powerful alternative to the Riemann integral that we have dealt with so far. This new, more modern piece of mathematics is due to the work of Henri Lebesgue, a French mathematician who lived from 1875 to 1941. To actually define the Lebesgue integral, we will first develop some core ideas … [Read more...] about The Lebesgue Integral: A Newer and More Flexible Alternative to the Riemann Integral
Partial Differential Equations Meet Electricity & Magnetism: Maxwell’s Equations, Poisson’s Equation, and Eigenfunctions of the Laplacian
Welcome back. Over the last few weeks, we have studied what I hope are some fascinating results in mathematics. We have developed the theory behind multivariable calculus and applied it to describe well-behaved fluids. We have also put the classic Riemann integral on rigorous footing and proven the second Fundamental Theorem of Calculus. This week, we will continue our journey … [Read more...] about Partial Differential Equations Meet Electricity & Magnetism: Maxwell’s Equations, Poisson’s Equation, and Eigenfunctions of the Laplacian
Predicting the Path a Particle Will Take in a Fluid: A Brief Overview
I hope that all of my readers have had a restful Thanksgiving Break and are ready to begin their final exam studies. This week, we will discuss how to design a numerical program that will predict the path a particle will take in a real-world fluid flow. To do this, we must first outline our overall problem. Suppose that we have mounted a wing inside a wind tunnel. When we … [Read more...] about Predicting the Path a Particle Will Take in a Fluid: A Brief Overview