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Visually stunning math concepts which are easy to explain

Does $\pi$ contain all possible number combinations?

Proofs that every mathematician should know. [closed]

Fourier transform for dummies

Find five positive integers whose reciprocals sum to $1$

Zero to the zero power – is $0^0=1$?

Is it true that $0.999999999\dots=1$?

Can't argue with success? Looking for “bad math” that “gets away with it”

How do I convince someone that $1+1=2$ may not necessarily be true?

Find a real function $f:\mathbb{R}\to\mathbb{R}$ such that $f(f(x)) = -x$?

Looking for an intuitive explanation why the row rank is equal to the column rank for a matrix

Are “if” and “iff” interchangeable in definitions?

Is there an integral that proves $\pi > 333/106$?

Am I just not smart enough? [closed]

What makes a theorem “fundamental”?

Can someone clearly explain about the lim sup and lim inf?

“Simple” beautiful math proof [closed]

Determinant of a non-square matrix

What are the applications of functional analysis?

Are the eigenvalues of $AB$ equal to the eigenvalues of $BA$? (Citation needed!)

Use of “without loss of generality”

What exactly is a number?

Introductory texts on manifolds

Differentiating an Inner Product

Is $dx\,dy$ really a multiplication of $dx$ and $dy$?

Entire function bounded by a polynomial is a polynomial

What's the proof that the Euler totient function is multiplicative?

what functions or classes of functions are $L^1$ but not $L^2$

What is magical about Cartan's magic formula?

Is Inner product continuous when one arg is fixed?