How Euler Tackled an innocent-looking integral

For unclear reasons, I really wanted to write down one wacky (read: elegant) calculus exercise tonight -- have you integrated the cotangent function twice? I feel the infinite series are mere toys dancing at the fingertips of Euler, and consider his method to tackle this quite beautiful, my usual attitude towards Euler math. For some … Continue reading How Euler Tackled an innocent-looking integral

QuickType Scientific Symbols [Updated June 26th]

Some of my text-friends ask me how I can quickly type out mathematical symbols when we are discussing homework problems. Well, for one, I enabled the Greek keyboard on my phone, and then there's this: taking advantage of the automatic text-replacement system built right in macOS and iOS. To use this table, on iOS and … Continue reading QuickType Scientific Symbols [Updated June 26th]