### New applet: What does b do in a quadratic function?

30 June 2017

y = ax2 + bx + c is a parabola. Changing the variables a and c are fairly simple, but what does b actually change, and by how much?

### New applet: Domain and range investigation

9 May 2017

This interactive applet allows you to explore the concepts of domain and range for several different mathematical functions.

### Math movie: The exceptional life of Benjamin Banneker

19 February 2017

Self-taught mathematician and astronomer Benjamin Banneker excelled despite little formal education and prejudice.

### What’s the correct graph of sec(arccos(x))?

29 January 2017

Here we solve another graph mystery - what is the correct domain for y = sec(arccos(x))? And why do different software packages show similar, but different graphs?

### Review: Manga Guide to Regression Analysis

3 September 2016

The Manga Guide to Regression Analysis continues the tradition of presenting math through comics. Here's my review.

### SquareCirclez is a “Top 100” math blog!

29 August 2016

I was humbled this week to receive notice that SquareCirclez (the IntMath Blog) has been included in a list of the "Top 100 Math Blogs".

### The real story behind the Tesla Map to Multiplication chart

10 July 2016

The fascinating Map to Multiplication may not be all it seems, notwithstanding its cleverness.

### Intersection of 3 planes at a point: 3D interactive graph

28 June 2016

This 3D planes applet allows you to explore the concept of geometrically solving 3 equations in 3 unknowns.

### Conic sections interactive applet

25 May 2016

This interactive applet allows you to explore the concept of slicing a cone by a plane at various angles and positions, resulting in conic sections.

### Geometric shapes in ancient rock art paintings

19 April 2016

Ancient rock art may give clues to the origin of written symbols, including early math notation.

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