Rank: Advanced Member Groups: Registered, Advanced Member Joined: 06/04/2023(UTC) Posts: 340 Was thanked: 26 time(s) in 25 post(s)
|
My students were building a multifocal ellipse and... almost went crazy. My ellipse is correct, but the student's is incorrect. Although the formulas are the same. Can you guess where the error is and whether it is necessary to modify SMath so that such an error is visible? Do you know more some examples? Ellipse4.sm (12kb) downloaded 10 time(s).Edited by moderator 08 September 2023 12:53:02(UTC)
| Reason: marked as SOLVED (not a bug)
|
|
|
|
Rank: Advanced Member Groups: Registered
Joined: 23/12/2011(UTC) Posts: 319 Location: italy Was thanked: 109 time(s) in 93 post(s)
|
In fact only apparently the written formula is the same but in the first case "S" is outside the summation while in the second case it is inside the summation. You can verify this by copying and pasting the two formulas into a text editor.
sergio
|
1 user thanked PompelmoTell for this useful post.
|
|
|
Rank: Advanced Member Groups: Registered
Joined: 23/03/2016(UTC) Posts: 277 Was thanked: 91 time(s) in 57 post(s)
|
|
|
|
|
|
Rank: Advanced Member Groups: Registered, Advanced Member Joined: 13/01/2012(UTC) Posts: 2,648 Location: Italy Was thanked: 1331 time(s) in 876 post(s)
|
Originally Posted by: PompelmoTell In fact only apparently the written formula is the same but in the first case "S" is outside the summation while in the second case it is inside the summation. You can verify this by copying and pasting the two formulas into a text editor.
sergio You can also select/double-click the sum symbol to check what belongs to it. |
If you like my plugins consider to support SMath Studio buying a plan; to offer me a coffee: paypal.me/dcprojects |
2 users thanked Davide Carpi for this useful post.
|
on 07/09/2023(UTC), on 07/09/2023(UTC)
|
|
Rank: Advanced Member Groups: Registered
Joined: 10/12/2009(UTC) Posts: 248 Location: Cali, Colombia Was thanked: 87 time(s) in 66 post(s)
|
The problem is that in the first Ellipse(x,y) definition, variable S is outside Sum function, but in the definition of your students is inside: Your definition: Ellipse(x,y):sum(sqrt((x-el(X.F,i))^2+(y-el(Y.F,i))^2),i,1,N)-S Student´s definition: Ellipse(x,y):sum(sqrt((x-el(X.F,i))^2+(y-el(Y.F,i))^2)-S,i,1,N) Maybe, this explicit form is most clear for students: Edited by user 07 September 2023 18:06:56(UTC)
| Reason: Not specified
|
1 user thanked oscampo for this useful post.
|
|
|
Rank: Advanced Member Groups: Registered, Advanced Member Joined: 06/04/2023(UTC) Posts: 340 Was thanked: 26 time(s) in 25 post(s)
|
Better so
|
1 user thanked OchkovVF for this useful post.
|
|
|
Rank: Advanced Member Groups: Registered
Joined: 28/08/2014(UTC) Posts: 1,356 Was thanked: 815 time(s) in 516 post(s)
|
|
|
|
|
Rank: Advanced Member Groups: Registered, Advanced Member Joined: 06/04/2023(UTC) Posts: 340 Was thanked: 26 time(s) in 25 post(s)
|
It if Mathcad 15 1 ln(x) 2 ln*x - why not
|
|
|
|
Forum Jump
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.