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**Mathegocart****Member**- Registered: 2012-04-29
- Posts: 1,667

On math Cats theres lots of interactive stuff

but this is my fav.

http://www.mathcats.com/explore/encyclo/encyclogram.html

its really fun.

The integral of hope is reality.

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**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,657

hi mathgogocart

Thanks for the link; that's a great site.

Way, way back when I did A level physics I learnt about lissajous figures. We had a double pendulum (imagine a kid's swing with another smaller one attached below it but swinging at 90 degrees to the first. Below pendulum two was a leaky sandbag so that as each pendulum was set swinging the resultant trace of the trail of sand was a lissajous figure.

I thought that was quite fun. But then the dark ages passed and they invented computers. And I wrote a 10 line BASIC program to make the figures with the two rates of swing as independent variables. It was for a competition where you had to make a program that did something useful in 10 lines. (I didn't win because I was the teacher, setting up the task, and it was my demo)

Basically you just need two sine curves, one for the x coordinate and a different one for the y coordinate.

Bob

Children are not defined by school ...........The Fonz

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

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**Mathegocart****Member**- Registered: 2012-04-29
- Posts: 1,667

Awesome.

The integral of hope is reality.

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