Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: Solving Transcendental Equations ~ sin(x)/x
Replies: 3   Last Post: Nov 26, 2012 5:17 AM

 Messages: [ Previous | Next ]
 Christopher Creutzig Posts: 323 Registered: 2/24/09
Re: Solving Transcendental Equations ~ sin(x)/x
Posted: Nov 26, 2012 5:17 AM

On 11.10.12 06:33, ehahn wrote:
>>> syms y;
>>> p=0;
>>> k = -2*pi;.01:2*pi;
>>> s='P*sin(y*a)/(y*a)+cos(y*a)=cos(x*a)';
>>> solve(s)

> Warning: Explicit solution could not be found.

I'm not sure why you included setting values for p and k above, you are
not even trying to use them. And if you did, that would not work as long
as you kept using string input to solve.

Besides, I'm not sure what kind of answer you expect. In set notation,
and ignoring special cases like a=0, any x from the set

{ / P sin(a y) \ | }
{ acos| cos(a y) + ---------- | + 2 pi k | }
{ \ a y / | }
{ -------------------------------------- | k in Z_ } union
{ a | }

{ / P sin(a y) \ | }
{ acos| cos(a y) + ---------- | + 2 pi k | }
{ \ a y / | }
{ - -------------------------------------- | k in Z_ }
{ a | }

would be a solution ? where that set with a bar in there means ?the set
of all such-and-such, where k ranges over the integers.? In which format
should MATLAB give you this answer so it helps with your next
computation steps?

Christopher

Date Subject Author
10/11/12 ehahn
10/11/12 Torsten
10/11/12 Alan Weiss
11/26/12 Christopher Creutzig