OneMeterWonder

I'm currently trying to update a work Excel sheet with some conditional formatting to change the highlight color of each row when the current date and time is past the date and time in some reference cells. See here.

This is only a representative sample since I can't share work info, but basically what I want is for a row to change when either the date is past the date in cell B4 or the date is equal to B4 and the time is past the last time in each row of the East Coast column. I can understand the basic logic of how to do this, I just am not familiar enough with Excel's implementation of certain things or which functions are available to solve this problem ea

I've been helping someone with cleaning up a Google Sheets worksheet that involves a column of phone numbers. All but one of them is in the standard US format. I'd like to make a simple custom format that accounts for the standard formatting of a number based on country code.

I actually have a way to manage this that's good enough for what's needed, but I got curious about generalizing and realized I'm not really familiar enough with Sheets or Excel to have a good answer. How can one write a custom numerical format that is conditional upon the country code?

Bonus: I think it would be neat to figure out how to rig this up to compute the most frequent country code present in a range, then ma

In my, nearly nonexistent, free time, one of my current side interests is finally going back and properly learning some complex analysis. In particular, I’d like to have a better handle on contour integration.

Now, I of course took a complex analysis course in my undergrad and so I am familiar with standard Cauchy-Gorsaut, Jordan’s Lemma, and Residue methods. These all work for the standard meromorphic functions that one sees in a course like that.

But what about functions such that the set of singularities has cluster points or perhaps contains a continuum? A simple example would be something like

f(z)=(e^(1/z)-1)^(-1) or

g(z)=tan(1/z)

Neither of these are meromorphic as z=0 is both si

I'll preface with I don't study differential equations and have at best a scattered understanding of parts of the theory.

When teaching or studying intro DE's, we pretty universally cover the Laplace transform as a method of solving constant coefficient linear IVPs. Some courses will also go over power series solutions to equations with nonconstant coefficients and, if they're lucky, possibly the Method of Frobenius.

Here's what I'm curious about: The motivation and ideas leading to the development of the Laplace transform itself are almost never taught. Things like the historical study of various integral forms and the extension of power series to a continuous indexing variable.

**Is t

I seem to frequently run into the problem of students not understanding or recognizing the difference in data types. E.g. taking the norm of a scalar quantity, scalars being “computed” as vectors, failing to even understand what an object is, not recognizing that definitions are precisely formulated, etc. Just all over the place stuff.

I know this is partially to do with newness of material and blah blah whatever etc. I don’t really care about why anymore. What I do care about is whether anybody has managed to find any good resources or strategies that help to explain this kind of “meta” topic. I’m especially interested if it’s something that you’ve had personal experience with being a su

I have been studying some optical physics on the side of my usual work (I am not a physicist) and I recently have been studying the mathematical expression of the Huygens-Fresnel Principle for modeling plane and spherical waves. I'm aware that in this model, all points p on a wavefront surface S at a given time t act as point sources and can be integrated to find the contribution at a further point q in space. So diffraction in this model is a natural consequence of these point sources extending when a plane wave reachs the far edge of a slit in a material.

However, it seems that typically the material in which the slit is made is assumed to allow no transmission of incident waves. (In fact

I'm teaching a mathematics course this coming Fall and I'm considering changing the modality of some of my assignments. Typically I will build simple assignment pages in Canvas and require a pdf submission. This started out a little rough, but seems to have become standard and most students can at least manage to turn things in this way. However, I have a few bones to pick with this method.

• Complete non-uniformity among assignments. Some students use Word to write some of their submissions, some handwrite them and upload pdfs that are just JPEGs or HEICs embedded into a Word file and exported to PDF.

• If they write completely in Word, they usually have zero formatting skill or write eve