Trigonometry, nspire and answers

[nunocasteleira]

Hi,
This is my first post on the Group.
I'm learning trigonometry and I have a question.
For example, sin(pi/3) = sqrt(2)/2, but if I calculate this result on
my nspire I get 0,7071...
Is there any way of getting the answer of sqrt(2)/2?
Thanks in advance,
Nuno João Casteleira

[Andy Kemp]

Sadly no, the TI-Nspire (numerical) will only return decimal answers.  The TI-Nspire CAS will give you the answer in surd form, but you need to check if it is allowed for the course you are working towards...

--
To post to this group, send email to tins...@googlegroups.com
To unsubscribe send email to tinspire+u...@googlegroups.com
For more options, visit this group at
http://groups.google.com.au/group/tinspire?hl=en-GB?hl=en-GB
The tns documents shared by group members are archived at
http://lafacroft.com/archive/nspire.php

[Nelson Sousa]

and sin(Pi/3) is sqrt(3)/2, not sqrt(2)/2 :)

Nelson

[Steve Arnold]

Of course, if you are happy to use a function or program in a prepared document, then most things like this can be achieved.

If you download the file "radicals.tns" from the Google Files section of the site, as well as containing several quiz programs to help you learn and practise converting and simplifying radical expressions, there is a little program called "radicalsimp()" that does what you require for simple examples.

So for example,

radicalsimp(1.4142) -> √(2)

radicalsimp(sin(pi/3)) -> √(3)/2

radicalsimp(3sqrt(12)) -> 6√(3)

radicalsimp(√(42/3)) -> √(14)

etc

Please note that in order to recognise approximations like 1.414 and 1.732 as their corresponding square root values, there is a low tolerance built in, so you may get some screwy answers for harder ones - nothing I can do about that.

It will also not recognise radical expressions like 1+√(5) - only multiples of radicals.

If you drop this document into your MyLib folder and refresh Libraries (from the Doc menu) then you will find the program in your Catalog from any document you are in.

Of course, documents like this are probably not going to be allowed in an exam, but they can be helpful to explore and to learn these skills.

Steve

 

--
To post to this group, send email to tins...@googlegroups.com
To unsubscribe send email to tinspire+u...@googlegroups.com
For more options, visit this group at
http://groups.google.com.au/group/tinspire?hl=en-GB?hl=en-GB
The tns documents shared by group members are archived at
http://lafacroft.com/archive/nspire.php

--
With best wishes,
Steve
_________________
Dr Stephen Arnold
Educational Technology Consultant
Compass Learning Technologies

T3 Fellow, Teachers Teaching with Technology Australia

Office: +61-2-4232-2080
Mobile: +61-4-0175-3834
Web: http://compasstech.com.au
_________________   

[Andy Kemp]

I hope in time this will come as a native feature on the Non-CAS as it is now standard on many of the Scientific calculators...  If there are really exam boards out there that don't want to allow this feature (although I can't think why!) then it could always be added as another setting for P2T...

At the moment all my IB students end up having an Nspire and a £7 Casio Scientific (FX83GT)  to they can do these types of calculations in surd form (radicals?) and multiples of pi (for inverse functions).

[Eric Findlay]

This is a tricky one, since the exam boards (at least in BC, Canada)
specify that you cannot use a calculator with a CAS. Doing sqrt(3)/2
would certainly classify as CAS, as it's symbolic manipulation.

However, the scientific calculators are allowed because the statement
"All scientific calculators" was put into practice before the sqrt was
ever displayed in an answer on a calculator. Heck, I didn't even know
they did this until I saw some Chinese calculators this summer that did
that.

--
For I am convinced that neither death nor life, neither angels nor
demons, neither the present nor the future, nor any powers, neither
height nor depth, nor anything else in all creation, will be able to
separate us from the love of God that is in Christ Jesus our Lord.
- Romans 8:38-39 (NIV)
--
Eric Findlay
AKA Eagle-Man

> <mailto:nunoj...@gmail.com>> wrote:
>
> Hi,
> This is my first post on the Group.
> I'm learning trigonometry and I have a question.
> For example, sin(pi/3) = sqrt(2)/2, but if I calculate this
> result on
> my nspire I get 0,7071...
> Is there any way of getting the answer of sqrt(2)/2?
> Thanks in advance,
> Nuno João Casteleira
>
> --
> To post to this group, send email to tins...@googlegroups.com

> <mailto:tins...@googlegroups.com>

> To unsubscribe send email to
> tinspire+u...@googlegroups.com

> <mailto:tinspire%2Bunsu...@googlegroups.com>

> For more options, visit this group at
> http://groups.google.com.au/group/tinspire?hl=en-GB?hl=en-GB
> The tns documents shared by group members are archived at
> http://lafacroft.com/archive/nspire.php
>
>
>
>
> --
> With best wishes,
> Steve
> _________________
> Dr Stephen Arnold
> Educational Technology Consultant
> Compass Learning Technologies
>
> T3 Fellow, Teachers Teaching with Technology Australia
>
> Office: +61-2-4232-2080
> Mobile: +61-4-0175-3834
> Web: http://compasstech.com.au
> _________________
>
> --
> To post to this group, send email to tins...@googlegroups.com

> <mailto:tins...@googlegroups.com>

> To unsubscribe send email to tinspire+u...@googlegroups.com

> <mailto:tinspire%2Bunsu...@googlegroups.com>

> For more options, visit this group at
> http://groups.google.com.au/group/tinspire?hl=en-GB?hl=en-GB
> The tns documents shared by group members are archived at
> http://lafacroft.com/archive/nspire.php
>
>
> --
> To post to this group, send email to tins...@googlegroups.com
> To unsubscribe send email to tinspire+u...@googlegroups.com
> For more options, visit this group at
> http://groups.google.com.au/group/tinspire?hl=en-GB?hl=en-GB
> The tns documents shared by group members are archived at
> http://lafacroft.com/archive/nspire.php
>
>
>
>

> No virus found in this incoming message.
> Checked by AVG - www.avg.com
> Version: 9.0.862 / Virus Database: 271.1.1/3187 - Release Date: 10/09/10 11:34:00
>