sin(x)/x solve,x

[ValeryOchkov]

I would like to show my students a symbol math in Mathcad and in Internet. But:

[Werner_E]

Its well known that Mathcad's symbolics unfortunately is very weak and in no way state of the art.

Here it misses the fact that your function is undefined for x=0. It gets even worse, if you tell Mathcad to omit x=0:

Its beyond my understanding why we get -72*pi now and why MuPad switches to float mode.

The symbolics seem sto consider the nominator only in these cases and finds a wrong "solution", similar as in the following:

BTW, WolframAlpha's result could be simplified to

so its not perfect, either, but at least the result given is correct.

[AlanStevens]

How about:

(sinc(x) is Mathcad's built in function for sin(x)/x; though, if you prefer, you could replace it with sin(x)/x in the above and would get the same results)

Alan

[ValeryOchkov]

Thanks, but

[AlanStevens]

Yes, that's why I gave the solution in two separate ranges.

For some reason Mathcad insists on giving x=0 as a solution if the range crosses from negative to positive. I suspect it is actually just solving sin(x) = 0.

Alan

[ValeryOchkov]

AlanStevens wrote:

Yes, that's why I gave the solution in two separate ranges.

For some reason Mathcad insists on giving x=0 as a solution if the range crosses from negative to positive. I suspect it is actually just solving sin(x) = 0.

Alan

Yes!

We have in old Mathcad (11 and < ?) 0/0=0 (0/something=0)..

Now we have a correct answer - an error message.

[ValeryOchkov]

One Buridan's ass problem

https://en.wikipedia.org/wiki/Buridan%27s_ass

y(x):=sin(x)/x x:=0 root(y(x), x)= ???

I think we use the Newton method in Prime (???=error)

http://communities.ptc.com/videos/1411

and the secant method in Mathcad 15 (???=1910 pi)

http://communities.ptc.com/videos/1466

PS

*** not from me but from PlanetPTC