`sin^2x + cos^2x = 1`
`y = frac (-b +- sqrt(b^2 - 4ac)) (2a)`
`(x + 2)^2 + (y - 3)^2 = 16`
`slope = m = frac (\text(change in y)) (\text(change in x)) = frac (Deltay) (Deltax)`

Get Math Help!

Interesting and Fun Math Articles

Math with Bad Drawings

Lover of math. Bad at drawing.

Puzzle Planet.

( Mar-11-2026)

A new book needs you.... Read more


Curves to curve by.

( Oct-30-2025)

A guide for teachers looking to fix up their test scores.... Read more


10 best triangles of the 21st century (so far).

( Oct-14-2025)

The definitive ranking.... Read more


Oxbridge of America

( Sep-23-2025)

A plea, not to end snap judgments, but merely to better calibrate them.... Read more


Is math discovered or invented?

( Aug-25-2025)

Four completely satisfying answers.... Read more


The mathematics of “are we there yet?”

( Aug-18-2025)

Will the Marvel Cinematic Universe outlast human civilization? Unlikely, but not impossible.... Read more

Math with Bad Drawings

Lover of math. Bad at drawing.

Puzzle Planet.

( Mar-11-2026)

A new book needs you.... Read more


Curves to curve by.

( Oct-30-2025)

A guide for teachers looking to fix up their test scores.... Read more


10 best triangles of the 21st century (so far).

( Oct-14-2025)

The definitive ranking.... Read more


Oxbridge of America

( Sep-23-2025)

A plea, not to end snap judgments, but merely to better calibrate them.... Read more


Is math discovered or invented?

( Aug-25-2025)

Four completely satisfying answers.... Read more


The mathematics of “are we there yet?”

( Aug-18-2025)

Will the Marvel Cinematic Universe outlast human civilization? Unlikely, but not impossible.... Read more

Feature Column


Weekly Maintenance Message

( Apr-03-2026)

Weekly Scheduled Maintenance Notice This blog is temporarily unavailable as we perform our regularly scheduled weekly maintenance. These updates are part of our ongoing effort to ensure the platform remains stable, secure, and performant for all users. During this maintenance window, you may experience intermittent disruptions in access, including delays... Read more


Puzzling Like the Seventeenth Century

( Apr-01-2026)

Though the chart starts out in alphabetical order, there's a break in the pattern that offers a clue... Puzzling Like the Seventeenth Century Ursula Whitcher Mathematical Reviews (AMS) The following chart is taken from the second edition of a German-language arithmetic textbook by Anton Schultze. It was published in Liegnitz... Read more


How to Untwist Your Fractions

( Mar-01-2026)

You could pick up the torus and rotate it horizontally, as though you are taking the lid off of a jar of peanut butter... How to Untwist Your Fractions Diana Davis Phillips Exeter Academy A string around a bagel Here's the problem: your bagel has a torus knot wrapped around... Read more


Does Mathematics Progress?

( Feb-01-2026)

Every time some mathematical question is answered, it generates new mathematical issues to think about.... Does Mathematics Progress? Joe Malkevitch York College (CUNY) Introduction With the beginning of a New Year—2026 in one system of counting, though not all societies use the same calendar—many people take the opportunity to examine... Read more


Information, Insight, and the Problem With Parameters

( Jan-01-2026)

Could we possibly gain more insight by trading away even more information? Information, Insight, and the Problem With Parameters Anil Venkatesh Adelphi University Introduction I have two data sets for us to consider. Both consist of observations of a single variable. Data Set 1 holds the daily number of positive... Read more


Everything I Need to Know About Polygons I Learned from My Pre-Kindergartner

( Dec-01-2025)

This fall I woke up to a surprise comprehensive exam, with my toddler as the examiner, starting with the demand for a nonconvex regular [simple] polygon. It was 4:30 am. I had not yet had coffee. Everything I Need to Know About Polygons I Learned from My Pre-Kindergartner Courtney Gibbons... Read more

Feature Column


Weekly Maintenance Message

( Apr-03-2026)

Weekly Scheduled Maintenance Notice This blog is temporarily unavailable as we perform our regularly scheduled weekly maintenance. These updates are part of our ongoing effort to ensure the platform remains stable, secure, and performant for all users. During this maintenance window, you may experience intermittent disruptions in access, including delays... Read more


Puzzling Like the Seventeenth Century

( Apr-01-2026)

Though the chart starts out in alphabetical order, there's a break in the pattern that offers a clue... Puzzling Like the Seventeenth Century Ursula Whitcher Mathematical Reviews (AMS) The following chart is taken from the second edition of a German-language arithmetic textbook by Anton Schultze. It was published in Liegnitz... Read more


How to Untwist Your Fractions

( Mar-01-2026)

You could pick up the torus and rotate it horizontally, as though you are taking the lid off of a jar of peanut butter... How to Untwist Your Fractions Diana Davis Phillips Exeter Academy A string around a bagel Here's the problem: your bagel has a torus knot wrapped around... Read more


Does Mathematics Progress?

( Feb-01-2026)

Every time some mathematical question is answered, it generates new mathematical issues to think about.... Does Mathematics Progress? Joe Malkevitch York College (CUNY) Introduction With the beginning of a New Year—2026 in one system of counting, though not all societies use the same calendar—many people take the opportunity to examine... Read more


Information, Insight, and the Problem With Parameters

( Jan-01-2026)

Could we possibly gain more insight by trading away even more information? Information, Insight, and the Problem With Parameters Anil Venkatesh Adelphi University Introduction I have two data sets for us to consider. Both consist of observations of a single variable. Data Set 1 holds the daily number of positive... Read more


Everything I Need to Know About Polygons I Learned from My Pre-Kindergartner

( Dec-01-2025)

This fall I woke up to a surprise comprehensive exam, with my toddler as the examiner, starting with the demand for a nonconvex regular [simple] polygon. It was 4:30 am. I had not yet had coffee. Everything I Need to Know About Polygons I Learned from My Pre-Kindergartner Courtney Gibbons... Read more

Joel David Hamkins

mathematics and philosophy of the infinite

The spectrum of consistency strengths for membership in a computably enumerable set, Notre Dame Logic Seminar, April 2026

( Apr-04-2026)

This will be a talk for the Logic Seminar at the University of Notre Dame, 14 April 2026, 2pm, Room 125 Hayes-Healey. Abstract After establishing several  general features of the hierarchy of consistency strength, we shall consider the possible spectrum … Continue reading ... Read more


The Book of Infinity, MIT Press, 2026

( Mar-28-2026)

I am very pleased to announce that The Book of Infinity is now available for pre-order. Check it out at your favorite booksellers. From the preface: Come, let us explore infinity! We shall visit all my favorite paradoxes and conundrums. The ancient … Continue reading ... Read more


Truth and paradox in the theory of finite and infinite games, Owens Memorial Lecture, Wayne State University, April 2026

( Feb-12-2026)

I am honored to be invited to give the Owen G. Owens Memorial Lecture at Wayne State University on 16 April 2026, joining a distinguished list of luminaries giving previous Owens lectures, including Gregory Margulis, John Milnor, Mikhael Gromov, John … Continue reading ... Read more


Mathematicians do not agree on the essential structure of the complex numbers, ASL/APA Central Division Meeting, Chicago, February 2026

( Feb-11-2026)

I have been asked by the ASL to fill in as a last-minute substitute speaker for the ASL session at the upcoming 2026 APA Central Division Meeting in Chicago, February 18-21, 2026, due to a late cancellation of one of … Continue reading ... Read more


Surreal arithmetic is bi-interpretable with set theory, CUNY Logic Workshop, March 2026

( Feb-04-2026)

This will be a talk at the CUNY Logic Workshop on 13 March 2026, held at the CUNY Graduate Center. Abstract. I shall introduce the elementary theory of surreal arithmetic (SA), a first-order theory that is true in the surreal field when equipped with … Continue reading ... Read more


The elementary theory of surreal arithmetic is bi-interpretable with set theory, Notre Dame Logic Seminar, November 2025

( Nov-12-2025)

This will be a talk for the Logic Seminar at the University of Notre Dame, Tuesday 18 November 20215 2pm 125 Hayes-Healy Building. Abstract. I shall introduce what I call the first-order elementary theory of surreal arithmetic, a theory that is true … Continue reading ... Read more

Joel David Hamkins

mathematics and philosophy of the infinite

The spectrum of consistency strengths for membership in a computably enumerable set, Notre Dame Logic Seminar, April 2026

( Apr-04-2026)

This will be a talk for the Logic Seminar at the University of Notre Dame, 14 April 2026, 2pm, Room 125 Hayes-Healey. Abstract After establishing several  general features of the hierarchy of consistency strength, we shall consider the possible spectrum … Continue reading ... Read more


The Book of Infinity, MIT Press, 2026

( Mar-28-2026)

I am very pleased to announce that The Book of Infinity is now available for pre-order. Check it out at your favorite booksellers. From the preface: Come, let us explore infinity! We shall visit all my favorite paradoxes and conundrums. The ancient … Continue reading ... Read more


Truth and paradox in the theory of finite and infinite games, Owens Memorial Lecture, Wayne State University, April 2026

( Feb-12-2026)

I am honored to be invited to give the Owen G. Owens Memorial Lecture at Wayne State University on 16 April 2026, joining a distinguished list of luminaries giving previous Owens lectures, including Gregory Margulis, John Milnor, Mikhael Gromov, John … Continue reading ... Read more


Mathematicians do not agree on the essential structure of the complex numbers, ASL/APA Central Division Meeting, Chicago, February 2026

( Feb-11-2026)

I have been asked by the ASL to fill in as a last-minute substitute speaker for the ASL session at the upcoming 2026 APA Central Division Meeting in Chicago, February 18-21, 2026, due to a late cancellation of one of … Continue reading ... Read more


Surreal arithmetic is bi-interpretable with set theory, CUNY Logic Workshop, March 2026

( Feb-04-2026)

This will be a talk at the CUNY Logic Workshop on 13 March 2026, held at the CUNY Graduate Center. Abstract. I shall introduce the elementary theory of surreal arithmetic (SA), a first-order theory that is true in the surreal field when equipped with … Continue reading ... Read more


The elementary theory of surreal arithmetic is bi-interpretable with set theory, Notre Dame Logic Seminar, November 2025

( Nov-12-2025)

This will be a talk for the Logic Seminar at the University of Notre Dame, Tuesday 18 November 20215 2pm 125 Hayes-Healy Building. Abstract. I shall introduce what I call the first-order elementary theory of surreal arithmetic, a theory that is true … Continue reading ... Read more