jrive

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3 years, 166 days

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These are replies submitted by jrive

@acer can you give me an example of when they're not equal? 

I always thought you could bring a product of numbers into the radical by squaring them ---that is what  I wanted to do with the result; put it in that form:

-v/(2 a w L) + sqrt((-4 a^2 R^2 + v^2)/(4 a^2 w^2 L^2))

@nm that's at a different skill level!  I'm surprised there isn't a Maple command to do this --sometimes it can be more meaningful to have the radical unsimplified. 

Can your solution be modified to  bring the 2 into the radical?

@mmcdara yeah...I'm talking resistances in the question and not impedances, so the values should all be real (and positive).  And, if Rhi > RLo, then

R2 = sqrt((Rhi - Rlo)*Rhi)

is valid....so I don't get it....why is the answer in (5) for R2 different than this answer?

@mmcdara R2 in the first solution of (3)  is a valid physical solution,

R2 = sqrt((Rhi - Rlo)*Rhi)

So, I'm thinking R2 in (5) should simplify to R2 in (3).   Can Maple do that simplification?  I proved out R1 by hand...but am too lazy to simplify R2 in (5) by hand....

and, if it doesn't simplify to the R2 in (3), then something is wrong (I think)...

@acer thank you.  Yes, that is what I would have expected  to get as an answer.  I was not aware of evala, so I need to read up on how/why it works.  

To @ Scot Gould 672 point, why doesn't simplify work given the "right" assumptions?

@acer thanks...do you know where I can find a list of which commands would return unevaluated.?

@Scot Gould thanks for the suggestion...I agree...looks like 150% is the way to go...

thanks!

@acer good eye...the space was the reason it didn't work for me the first time.  Thanks!

@Hullzie16 ---don't know what is different...but after retyping it it worked...

@Hullzie16 this is what I get....

@Joe Riel, indeed, I inadvertently (or maybe knew to do so at the tme, ;-)) had the first section which worked correctly named and language selected as Plain Text....thanks again.

@Joe Riel and @Carl Love thank you both for the responses.  I unfortunately do not use Maple as much as I would like to and find myself stumped by some of the errors I get (because I don't fully understand how Maple works).   I appreciate the help.  Syrup is a great toolbx for Maple.

So my issue was that the document I uploaded was a section from another document in which I had two identical sections, configured differently (with a 'restart') in between.  The first section ran without issues,but the second one complained.  In the first section, I must unknowingly have done what Joe said because it worked fine.   I need to go back and check!

Thank you both,

Jorge

@Carl Love  --got it,..thank you!

@Carl Love thank you for your response.  What do you mean by nontrivial solution?  I wanted x1 and x2 expressed in terms of DC and T, instead of ton and toff.

@acer thank you for your response, that solution gives me what I am looking for.  But, out of curiosity, how else might I have asked the question to be more clear?  How should, " solve this equation in terms of x,y,z" be phrased?   The intent with that phrase (or phrasing) is that the solution be expressed in terms of those variables, using whatever relationships are available between those variables and the ones in the solution they can "replace"...I wouldn't know how else to say that, so I look forward to your response!

In my my case, I didn't want ton or toff in the solution, but instead wanted it expressed in tems of DC and T which have relationships to ton and toff, and each other, as shown in eqs 3 and 4.....

anyway, you understood what I meant, so much appreciated.

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