Announcements regarding our community
New editor released!

We've heard many requests to make it even easier to create rich content. It's always been our goal to create a system which empowers everyone with a vision of an interactive lesson to turn it into reality - without needing to know how to program. :)

Our first version, eML, helped to reduce the barrier significantly, but today, we've released an even easier-to-use lesson editor! It's still under intense development, and so you'll see it grow through leaps and bounds over the next few days. Give it a spin, and share your feedback! We'd be happy to improve it to the liking of our community. :)

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Girls on expii!

Attention all females of the expii community! Po-Shen Loh and I started a Facebook page for all the girls on expii so that we can boost the number of girls on this site (and hopefully in the world of mathematics in general) and inspire other young girls to be interested in math as well! If you're interested in joining, please find us on Facebook and we'll add you to the page!

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Let's build Algebra 1 and 2! Discuss content creation here.
Distributive Property

@Benjamin We have the distributive property here: https://www.expii.com/map/9124 (if you search "distributive property" this is the first result).

It's possible that it's missing somewhere else though---were you looking for it somewhere else? Let us know.

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What is the point of Maths?

You need math to program video games.

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Let's build Astronomy! Discuss content creation here.
Astronomy Edit-a-Thon, 2015 October 22 16:00 Pacific / 19:00 Eastern Time

Hi Michael! When is the next astronomy edit-a-thon? :)

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Let's build Biology! Discuss content creation here.
Let's build Calculus! Discuss content creation here.
Expii as part of a Calculus II class

Got it - thanks @CassieTaylor !

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Specific useful substitutions article

@Moor-Xu There's also a https://www.expii.com/topic/5440 (Summary: How to Compute Integrals) topic now.

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Let's build Chemistry! Discuss content creation here.
Let's build Earth Science! Discuss content creation here.
Let's build Electricity and Magnetism! Discuss content creation here.
Impedance

@Michael-Busch Thanks a lot for the response; makes sense!

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Let's build Geometry! Discuss content creation here.
Constructible Numbers?

Hi everyone!

I'm new to expii, and I've only just started to explore all the content here. I noticed that there isn't yet a topic on constructible numbers; will that be coming in the future? I think I have some writing that could contribute to that topic.

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Weekly Global Jam Sat Feb 21: Constructions (11am Eastern / 9:30pm India / 5pm Central Europe)

OK, I've posted an explanation here:

https://www.expii.com/the-basic-constructions/

Feedback is welcome!

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Let's build Mechanics! Discuss content creation here.
Expii Jam on Wed Feb 25 at 9pm Eastern: Waves

Hi! Since @Po-Shen-Loh is currently on a plane to Munich en route to the Romanian Masters in Mathematics (wish team USA luck!), I'll be running this Jam today. Here's just some links to the pages about Waves that people can post in.

https://www.expii.com/frequency-and-period/
https://www.expii.com/peaks-troughs-wavelength/
https://www.expii.com/transverse-vs-longitudinal/
https://www.expii.com/phase/
https://www.expii.com/wave-velocity/
https://www.expii.com/interference/

Since all these links have at most 1 post and no exercises, any contribution is very very helpful! Feel free to ask any questions, discuss any ideas, write/edit articles, etc. I'll be writing about interference in the meantime.

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Expii Jam Wed Jan 28 at 9pm Eastern: Energy

Thanks @Harrison-Grodin for coming today! You can continue, but I think that I'm done writing for the day. Thanks for a good Jam! I'll keep this page open in case you have questions or comments.

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Let's build Thermodynamics! Discuss content creation here.
General talk about math
USA TSTST 2015 solutions

Hi!

Does anyone have the solutions for the USA TSTST 2015, especially problems 3 and 6, since there are no correct solutions posted on AoPS as of now?

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ARML!

We're sponsoring ARML this weekend! Visit our table for free expii t-shirts! :) We'll be at the Penn State site, near the song contest area. It's our pleasure to support the enthusiast community, from which we trace our own roots!

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General talk about non-math
Happy New Year!

Our New Year Present for everyone is the launch of Astronomy! :)

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Expii Revolution begun even on Quora

Click here to share knowledge and ask questions about Expii on Quora. Lot of people are waiting staff and knowledgable users to share about Expii on Quora.Hope you guys turn there.

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Trying to figure out how to use the site?
How do I delete a post?

@Po-Shen-Loh Can I get https://www.expii.com/t/existence-of-the-dodecahedron-1193?type=explanation&id=5144 deleted too, please? I accidentally typed this when I meant to type it in another tab, and saved it.

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Where is the Latex Tutorial?

I have used the Latex tutorial on AoPS.

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Got a feature request you'd like to see? Give us a shout here.
Profile Pictures for Expii.com main site accounts?

Hi Qinzhuo,

We pull profile images from gravatar. So if you add an image to the email you use for Expii, we'll pull it down.

Best,
Andrew

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Next Topic Button seems to be gone?

I remember a long time ago, there used to be a next topic button at the bottom of each page. I thought it seemed to be particularly useful. Can anyone tell me what happened to it?

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Having trouble with Expii? Let us know...
A few bug-reports about some Expii Solve problems

Re: 19.4, I am fairly sure that the answer is not 271 or 272. I got the answer it accepts and it's definitely correct, and I checked with wolfram|alpha.

The rest I agree at least somewhat with. I have my own bug report:

5.3: "The Stock Market": Okay, this is an okay problem with only minor potential ambiguities. I solved it, so I thought, but it said I was wrong. So I checked my work several times over and still got the same answer. Maybe I was interpreting the question wrong, I thought, so I tried some similar answers out but none of them worked. It says "round to the nearest whole percent", so I tried 0.xy, .xy, xy%, and also tried adding more digits, but nothing worked. Finally I just wanted to know what answer it accepted so I tried every single whole percentage from 0% to 100%; it accepted none of them. I did this again just to make sure I hadn't missed anything. Now I am still fairly confident that I had the correct answer to begin with, and it looks like the problem just doesn't accept it. I'd be happy to write a solution for it too, if I ever get the green box! What's so puzzling is that apparently 214 people have solved this question which does not appear to have an answer.

This is the last #3 question that I have not solved, and so would like to just be done with it at this point.

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Can't edit solution to Expii Solve problem

@Jacob-Zhang Thanks for reporting this! We're on it right now! :) @Daniel-Liu also messaged me about this. We really appreciate having such a responsive community!

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Share pointers to learning resources
Practice Resources

@Andrew-Yang
The books are fine if you get the PDF version of it and print it yourself.

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Applied Mathematics Book

same place

You mean Caltech?

By the way, someone suggested that all books should have this warning

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News from around the world
The Improving Mathematics Education in Schools (TIMES) Project

http://www.amsi.org.au/index.php/school-education-mainmenu/times-project
http://www.amsi.org.au/index.php/school-education-mainmenu/times-modules

Check these out! So many hidden gems in this world (the internet in particular). :) We'll definitely be consulting this for the upcoming Algebra map (which might include number theory and some counting as well)!

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The Algebra Project

Maybe this isn't news, but it is sort of for me. Have any of you heard of the Algebra Project before? I think it would be very interesting to connect with them at some point, although we would probably need to build an Algebra map (and establish a larger community) first. :)

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