Category: Technology

Categories
Technology

An Open Letter to My TI Friends

The good folks at Texas Instruments, at long last, have released an app for their popular Nspire product.  For geeky math folks like me, this was met with “I want to play.  I want to play.  I want to play!!!!”.  That is, until I visited the app store and found our that the app costs $29.99.  {insert sad face}

NspireSo…download, or don’t download?  I have been a sucker for all things TI for some time now, and the TI folks were kind enough to host me for their Fast Track program a few years back, where I received training on the Navigator system.  I’ve done many training sessions at my school for staff on graphing calculators, spoke at the T^3 conference one year, and wrote a grant last year for a class lab of Nspire CX’s.  When it has come to TI products in my school district…I’m all in!

HeartsBut despite out long relationship together, Texas Instruments, I’m thinking it may be time for us to break up.  It’s not you…it’s me.  See, I don’t see a future in this relationship, and I don’t know who you are anymore.  Remember last year when I bought all those glossy, snazzy Nspire-CX’s?  That was fun, and we have done some great lessons together.  But now I see you making the TI-84 color with new bells and whistles, and I can’t help but feel a little twinge of jealousy.  I don’t know what product I’m supposed to tell my students to buy anymore.  Some days you are Nspire, some days you are 84, and now this new app which a student could never possibly use on an SAT or AP exam….I just don’t know.

And your Nspire software?  I told all of my friends about how great you were, and bought a whole bunch of you in my grant last year.  But let’s face it, you take up way too much memory in my computer, and run way too slow at times.  And while the tns files are cool, and your new app plays them, I get tired of waiting for you sometimes.  Oh, and that free software offer on your website?  The one where I get free software if I buy the app?  I can’t help but feel a little hurt that you forgot about us who have purchased your software {sigh}…

Desmos PiSee, the thing is…I’m seeing someone else.  Her name is Desmos, and she is really cool.  I’ve told all my teacher friends about her, and they agree that she is really fast and reliable.  And while she doesn’t have all of your features, she is working on it.  We’re growing a nice relationship together.  She even makes me Pi when I need it.  And she is free!  (Note: OK, maybe this isn’t the best line for a break-up letter….but the Desmos calculator is free…check it out!)

I’m looking forward to seeing you at the T^3 conference next month, and I hope we can talk about our relationship.  But I don’t know if I see a future between us.

I hope we can still be friends.

Bob

Categories
Technology

It’s the End of Math as We Know It! (and I Feel Fine)

I’m a relatively new iPad user…just scratching the surface of the neat stuff out there, sometimes thinking how cool it would be to be back in the classroom with these tools, sometimes doing the slow burn when I see great tools go un-used. Every now and then I run into an app which has me running to my colleagues like a giddy schoolboy…such as today when a friend tweeted about the MyScript Calculator.

There’s really not much to this app:  you write a math calculation on the screen, and the app recognizes your handwriting, and performs the calculation.  It doesn’t solve equations, it doesn’t factor…it just calculates.   Check out my hairy knuckles as I take it for a test-drive.  Also, note that I understand that there are a number of goofy ways to record an iPad screen…I’m a newbie….baby steps….

It works for iPhone as well.  Take this app around your school, show it off to teachers, and enjoy the reactions and conversations.  Is this the end of the world?  Will we have a generation of kids who can’t make change for a 5?  Hey, it’s just a calculator…a pretty cool one.

So, how do we adapt math instruction in a world where computations are at our fingertips?  Ask better questions!

Categories
Algebra Technology

You Asked For Piecewise Functions, I Give You Piecewise Functions!

NEW: After popular demand from this post, I have created a tutorial on domain restrictions and piecewise functions.  Enjoy!


UPDATE: Many of my Desmos files are avilable on this page: Desmos File Cabinet Enjoy!

Let is never be said that mathcoachblog doesn’t listen to the needs of its followers!  One of the neat things about having a blog is checking out the routes people take to get to the blog. What search caused them to arrive here?  What countries are my visitors from?  What search phrases cause them to reach the blog?

Every day, without fail, there is a theme which appears in the search terms of blog visitors.  Here is a sampling of terms from just the last week:

  • Online piecewise graphing calculator
  • Graph a piecewise function online calculator
  • Piecewise function calculator online
  • Graphing piecewise functions calculator online
  • Piecewise functions online grapher
  • Online graphing calculator piecewise functions
  • How to do a piecewise function on Desmos

OK, folks I get it.  We want to graph piecewise functions.  So, let’s light this candle.

GRAPHING PIECEWISE FUNCTIONS ON DESMOS

The Desmos knowledge base provides instructions for graphing a piecewise function, and a neat video tutorial.  But I’ll provide a few examples here, and some teaching tips.  Let’s say we want to graph this piecewise function:

In the Desmos calculator, colons are used to separate domain restrictions from their functions.  And commas are used to have multiple function rules in one command.  So, the piecewise function above would be entered as:

Piecewise Entry

The function then appears quite nicely:

Function1

Sliders can be used to have students explore the continuity of a piecewise function.  Consider this problem:

For what value(s) of x is the piecewise function below continuous?

In Desmos, start by defining a slider for the parameter “a”.  For mine, I chose to limit the domain to between -10 and 10, and have step counts of .5.  Then, a can be used in the piecewise function.  Click the icon below to play with the document online.  The sharing features are another aspect of Desmos which have improved greatly in the past year.

SO, WHY ARE YOU AVOIDING “EQUALS” IN YOUR FUNCTIONS?

OK, smart guy, yes…yes, I have kinda avoided the equals parts of the domain restrictions.  Something neat (odd, goofy) happens when an equals is used in the domain restrictions.  Let’s graph this function:

Click this link to find out what happened when I tried to enter this function on Desmos.  The Desmos folks tend to monitor these things, so let’s see if they have a suggestion here.

Down the road, I want to take a deeper look at the new table feature, and will report out.  But my early impression is that it is a addition which works seamlessly with the existing, awesome, calculator.

Also, while I’m in a sharing mood, here is a quick file I created to use in an absolute value inequality unit.  Click below to check it out.  Would enjoy your input!

And finally, I started this post by sharing some of the search terms which cause people to find my blog.  Most of the time, I can explain those terms, and why people would end up here.  But this….well….this, I got nothing…..

search terms