Christopher2222

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10 years, 125 days

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These are answers submitted by Christopher2222

Myabe this will help you a little

restart:
for m from 1 to 100 do
     for n from 1 to 355 do
          if mod(n*m,355)=0 then print(n,m);
          end if
     end do
end do;

 With m=199 the only answer is n=355 since it's the only integer from 1 to 355 where mod(n*199,355)=0

 

Thanks

Or I could simplify your M with

M:=rand(1..K)();

 

I'm not sure if mathematica is mentioned anywhere in the show but from wikipedia it states "Wolfram Research (the maker of Mathematica) is the chief math consultant, reviewing scripts and providing background mathematics for the show." 

Thanks for the link correction, just take out the www in the address and it will work.  Here's the link:  http://numb3rs.wolfram.com I haven't had a good chance to fully read the links to each of the episodes, they seem to be done fairly well. 

Maybe someone could start a numb3rs blog here at mapleprimes and make worksheets associated to each episode. 

Okay thanks, I thought that's really the only way to do it. 

Sorry to play a little bit of devils advocate but wouldn't double or even triple digit numbers work? 

Something like 6997=7^(9+69) I know it's wrong and is not a solution but just as an example would such a solution exist?

So in order for Maple to return possible solutions I would need to set up a loop to try numbers and then return ones that are true. 

 

 

Sure

with(Student[Calculus1]):

c:=Roots(x^2-10-sin(x)-cos(x),x=-10..10,numeric);

But now I have to substitute those values into a to find the y intercept for each x (ie. subs(c[1],a); etc...) for all the intercepts.  I really don't want to have to do that. 

What I'd like to do is have Maple calculate the x,y intercepts in one step and show them to me.  This is what I've tried and I can't seem to prod it out of Maple. 

a:=y=x^2-10-10*sin(x);

b:=y=cos(x);

solve({a,b});  or solve({a,b},{x,y});

Returns x=RootOf ... and y=RootOf answers.  I try to evalf(%) or allvalues(%)  but I only get one answer

{x=-1.006881416,y=0.5344990470}

fsolve({a,b}); or fsolve({a,b},{s,y})   gives me another of the intercepts, but doesn't tell me all of them {x=-1.144307303,y=0.4136768823}  

fsolve doens't seem to like multiple equations specified over a range so I can't find all the intercepts using fsolve without having to first combine the equations and finding the roots and then use the subs command. 

So how can I get maple to produce the 4 points of intersection {x=..., y= ...} , {x= ... , y= ...} , {x= .. , y= ... } , {x= .. , y= ... } ?  

 

 

This is sort of along the same line of problem. 

a:= y=x^2-10-10*sin(x);

b:=y=2;

solve({a,b},{x,y});

Again only returns one solution, x as a RootOf and y=2 answer.  Using allvalues(%) returns the same answer.  Can't get the other 3 points of intersection with a single command. 

Thanks for all the options.  It seems like using Student[Calculus1] Roots seems to be the best option.

Using fsolve with avoid will still miss some roots if there are more than one root within the range. 

In my opinion I think fsolve should return all roots within a specified range.  Even if I use solve, I get a RootOf answer that I can't seem to coax out the real numbers for the roots. 

solve(x^2/20-10*x-15*cox(15+x));

-15 + RootOf( -300 cos(_Z) + 3225 - 230 _Z + Z^2)

 

I think he means what are the points where the lines cross as viewed from the plot and how can it be calculated.

So I asked a different question above in this thread.  Because it was somewhat related I posted in the same thread however it is a somewhat different topic should I start it as a new thread?  It may be an obscured question because it follows a topic already answered. 

So anyone know why my Ellipse and Parabola produce a 4 point solution when only 2 exist?

Thanks for the allvalues however when I use allvalues with an ellipse and parabola I get 4 points to the solution.

e1:=x^2/2500+y^2/200=1;

e2:=y=x^2;

solve({e1,e2},{x,y});

allvalues(%);

Gives me 4 points.  There's only two in the solution.  Why does it poduce 4?  Maybe I'm not understanding allvalues or how Rootof works but maybe it's a bug? 

It shows 2 points in the negative y quadrants like it's finding the mirrored parabola intersect points which is clearly not part of the solution.  The e2 equation never gets to negative y values let alone even crossing the ellipse there so I'm not quite sure why the solution of the 2 equations gives me those points.  Does allvalues just give every possible combination of -'ve and +'ve x's and y's even if it's not an answer to the solution?

Thanks Acer, you are right.  The reality is quite higher than one thinks.  I should've calculated it out. 

Any other ways to produce a random array?

Yes, more explanation.  Ahmedluss, can you explain a little more what your code does.  Some of us do not have Matlab.  Yes Maple can export and convert code to Matlab but it's apparent and unfortunate Matlab doesn't convert to Maple.  My first quick guess at what your code does, is some sort of insect growth population scenario. 

Okay thanks.  I've submitted the SCR. 

I was so, sooo close to wipeing out my hard drive and starting again.  Phew!  It was one of those Aha, woohoo I found it, eureka!  type moments.  Gotta love those every now and then. 

"Why is everything so heavy in the future?  Is there something wrong with earth's gravitational pull?" 

Okay, I finally found the problem. 

If Tools->Options->Display->Typsetting level is set to Extended ...  Precision round screen display will not work. 

That is interface(displayprecision=10); 

evalf(10.5);

10.5

This is what was causing all the problems I was seeing.  If I set the Typsetting level to Maple standard, everything works fine. 

interface(displayprecision=10);

evalf(10.5);

10.5000000000

You can try it for yourself and see the results I was getting.  Can someone file a report for that?

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