In knot theory, there are different ways to define a limit. The "geometric limit" looks at hyperbolic geometry of the knot exterior. The geometry of the exterior of twist knots looks more and more like (ie almost isometric to) the geometry of the exterior of the Whitehead link.

— Jessica S Purcell (@JessicaSPurcel1) March 6, 2022

It's not very intuitive how large the cumulative probability of an event is for which the annual probability is low. So I made this chart.

If the annual probability for some event is 1%, then the cumulative probability that this event happens within 100 years is 63%. pic.twitter.com/DIxyurBzpo

— Max Roser (@MaxCRoser) March 4, 2022

Primitive Pythagorean triple have the form (m^2 – n^2, 2mn, m^2 + n^2) for positive integers m and n, one odd and one even.

— Algebra Etc. (@AlgebraFact) March 3, 2022

T_n( cos(theta) ) = cos(n theta) where T_n is the nth Chebyshev polynomial of the first kind.

— Algebra Etc. (@AlgebraFact) March 2, 2022