Turn on suggestions

Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.

Showing results for

Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.

Showing results for

** Community Tip** - Learn all about PTC Community Badges. Engage with PTC and see how many you can earn!
X

- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Mute
- Printer Friendly Page

Dec 27, 2019
08:11 AM

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Notify Moderator

Dec 27, 2019
08:11 AM

help

Is it possible to get a more clear result, and how can I solve the two angles ?

Solved! Go to Solution.

1 ACCEPTED SOLUTION

Accepted Solutions

Dec 27, 2019
03:58 PM

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Notify Moderator

Dec 27, 2019
03:58 PM

@kenan2 wrote:

Okay is it possible to find a solution in the interval [pi ; 2*pi] ?

If you tell Prime via an "assume" statement it should deliver what you demand. In case of your (unsimplified) expression Prime/muPad has difficulties finding a solution so we can help a little by splitting the task into two parts:

You may experiment by adding "simplify" and/or "rewrite,asin" at the end of the second symbolic eval to see the very same result written in different ways.

BTW, this is another example where the new symbolic in Prime 6 fails to find a solution.

6 REPLIES 6

Dec 27, 2019
09:47 AM

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Notify Moderator

Dec 27, 2019
09:47 AM

Keep in mind that sqrt(x^2)=x is only valid if we can assume that x>0.

So in your result a and t cancel only if we assume that both are real and >0.

Dec 27, 2019
12:32 PM

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Notify Moderator

Dec 27, 2019
12:32 PM

Okay is it possible to find a solution in the interval [pi ; 2*pi] ?

Dec 27, 2019
03:58 PM

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Notify Moderator

Dec 27, 2019
03:58 PM

@kenan2 wrote:

Okay is it possible to find a solution in the interval [pi ; 2*pi] ?

If you tell Prime via an "assume" statement it should deliver what you demand. In case of your (unsimplified) expression Prime/muPad has difficulties finding a solution so we can help a little by splitting the task into two parts:

You may experiment by adding "simplify" and/or "rewrite,asin" at the end of the second symbolic eval to see the very same result written in different ways.

BTW, this is another example where the new symbolic in Prime 6 fails to find a solution.

Dec 28, 2019
04:51 AM

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Notify Moderator

Dec 28, 2019
04:51 AM

Thank you!

Another question, is it possible to remove all this red circles ?

Dec 28, 2019
08:42 AM

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Notify Moderator

Dec 28, 2019
08:42 AM

Yes. Define your A1, A2 Etc as a function of a and t. And follow through.

Success!

Luc

Success!

Luc

Dec 28, 2019
10:12 AM

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Notify Moderator

Dec 28, 2019
10:12 AM

@kenan2 wrote:

Thank you!

Another question, is it possible to remove all this red circles ?

Defining functions as Luc suggested is the mathematically cleanest way, but can get confusing if you have a lot of dependencies.

There are other ways, but they must be handled quite careful.

The red circles stem from the numerics, not the sybolics, because the expression cannot be evaluated numerically as a and t are not defined.

1) Following an assignment immediately by a symbolic evaluation cures that (I am not sure, why), but it doesn't look good to have the same or similar expression displayed twice

2) You can assign values to the variables (a, t) and then clear the variables for symbolic evaluation. You may hide those regions in a collapsed area. You may assign any numeric value but I prefer to assign NaN (Not-a-Number). So when accidentality a numeric evaluation is done later in the sheet, the problem can be spotted more easily.

Furthermore its a good idea to clear the variables completely whenever possible. But keep in mind that the already calculated variables (like Ix in my example) still keep their values!