The Farmer and the Mathematician 2
 The farmer is back, and he has a new mathematical friend helping him to make more sophisticated analyses of how best to use his central pivot irrigation equipment.
Packing circular segments into rectangles, triangles and trapezoids uncovers interesting geometry problems with theoretical as well as practical implications.
That and some really bad puns.
Preview the book here.


How to... Use css files in JavaScript export
 When you export a JavaScript app from Geometry Expressions, you get a particular default layout of the elements of the app. You can alter this layout, however, by specifying a css file (Cascading Style Sheet).
For example, a css which positions every element in the center of the window, rather than left justified would look like this:
#gxInputOutput { marginleft: auto; marginright: auto; }
#gxCanvas { padding: 5px; textalign: center; }
#gxHeader { textalign: center; }
#gxFooter { textalign: center; }
The css file is specified in the HTML5 / JavaScript Export dialog.
An app using the above style sheet can be viewed here.

Problem of the Month 
ABCDEFG is a regular heptagon.
I is the intersection of BD and CE, J is the intersection of CF and BE, K is the intersection of CG and BF, L is the intersection of AC and BG.
Show that B,C,I,J,K,L are vertices of a regular heptagon.
An interactive illustration is here. Can you generalize this result?

January Problem Solution:

CAD is an arc of a parabola with vertex A and focus B.
FGHI is the control polygon of a cubic spline.
Can you locate points FGHI so that the spline is exactly the parabolic arc? If so, where?
An interactive app which lets you play with this problem is here.
Clearly F and I should lie on C and D, and FG and IH should be tangents to the parabola. Playing with the interactive app suggests that positioning H and G 2/3 of the way to their intersection yields a good approximation to the parabola. Is this exact? A Geometry Expressions model confirms that it is: 



eBook Bundle

 The Tortoise and Achilles
 Calculus Explorations
 The Farmer and the Mathematician
 Developing Geometry Proofs
 101 Symbolic Geometry Examples
 101 Conic Sections Examples
 Using Symbolic Geometry to Teach Secondary School Mathematics
 Connecting Algebra and Geometry through Technology
 Function Transformations
 Exploring with Geometry Expressions
 The Farmer and the Mathematician II


eBooks

Sample chapters of other iPad eBooks are available hereInteractive math Apps which can be viewed on your iPad are available from Euclid's Muse


Videos

See our YouTube channel for videos exploring features in Geometry Expressions.
Watch more videos about creating Apps with Geometry Expressions.
Learn how to Export an Animation with Geometry Expressions. 

