Nspire Activity:Can you make my graph

[Ray Fox]

I used this activity and found it most beneficial to my students for mastering creating trig (sin & cos) equations from functions. The students really got into this challenging activity.

 

Very well done Amanda Williamson of Atlanta GA

 

Thanks

 

Ray Fox

Overton HS

Nashville, TN

[pam]

Ray,

Where can I find this activity? TIMath.com? The TI Activity Exchange?
It sounds like it would be a perfect activity for my classes in the
next few days.

Pam

[Tonya]

Here is the link:
http://education.ti.com/educationportal/activityexchange/Activity.do?cid=US&aId=9161

It is Activities Exchange Activity # 9161.

Tonya

> > Nashville, TN- Hide quoted text -
>
> - Show quoted text -

[Pat Flynn]

I have used this idea for all of my transformational graphing units
(trig, log's, parabolas, absolute values, etc.) The students really
get the idea of how the transformations work. In addition to the
transformaed graph, I also have the parent function graphed already on
the screen with its graph appearing as a dashed line. In that way,
the students can see if the graphs do in fact overlap when the
correcttransformations are made.

I have posted the one I use for trig called "play match the trig
graph."

[pam]

How do you keep students from just looking at the function rule?

They could do this in any number of ways:
-selecting the graph sometimes shows the rule (I know ways around this
one)
-right-clicking and selecting 'label' (you can change this label, too,
I think)
-pressing 'tab' and scrolling to the right function
-adding a function table
And those are only the ones that I can think of. My students are often
much more creative than I am.

So, the big question for me is: Is there any way to really hide the
rule from my students, forcing them to think about use transformations
to match the given graphs?

I tried to download Pat's file, but had no luck - right-clicked, but
did not have a 'save file as ... ' option. Any ideas for that?

Thanks and Happy New Year all!
Pam

[Paul Alves]

A good question. One way is to define your functions in a calculator page
and then graph them. If the student hovers over it, they will see for
example f1(x)=g(x) where g(x) has been defined rather than the function
rule. Another way is to avoid functions altogether and create a scatterplot
of points for a sequence of x values.
But as you said, a student who sets their head to it can find it out even
with these methods outlined.

Happy 2010!

Paul

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[Nelson Sousa]

the best (as far as I can think) way to hide a function's expression
is by creating the graph as a locus.

Create a text box somewhere out of sight with the formula you want
(remember that the position of text boxes is determined by window
settings). I like to change window settings to have xmax = 150 or so
and type in the formula on the right of the screen. Be creative.
Remember that formulas will appear at the coordinates where they were
created and will move around when window settings are edited. Of
course a student can see the formula if he changes the window settings
for something like -1million to +1million, so add a bunch of other
formulas just to set them off track ;)

Then create a point on the x-axis and display its coordinates.
Calculate the formula using the x-coordinate as parameter. Now use
measurement transfer and create a point over the y-axis. Create the
perpendiculars to the axis and create the intersection point. Now use
Locus to create the graph of the function.

Whenever you need to change the formula just edit the window settings
to see the formula you hid before and change it.

Loci don't have labels, they don't have equations, they don't have
atributes, nothing. They're just lines on the screen, there's no way
to cheat!

Let me know if you need any help with these steps.

Nelson

[pam]

Thanks, Nelson. I never think to make a locus. I think that will work
great.
Pam