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No need to hurry, esthetics is not a vital issue ... but thanks in advance.

PS : sorry for the syntax errors "waves" generated in the original Word document

Doing the following:

Why is int used when defining F not evaluated to x^2/2 when used to defined function F as shown in (2), when the int is evaluated when used separately in (3)?

I have lots of subsections for organization and have all the outputs at the end...  is there any way to force all/any sections/subsections to remain closed while the whole page is being evaluated? I still want the section to evaluate, but I want it to stay closed.

Is there a help page which explains why braces provide the partial text evaluation in this code?

RopeLen := 30;RopeAddLen := .5;

plots[textplot]([1, 1, typeset("%1", (({(1/2)*RopeLen}+{(1/2)*RopeAddLen})^2-{(1/2)*RopeLen}^2)^(1/2))])

Hello everyone,

I'm working on a simulation for standing wave to prove that the combination of 2 waves in opposite direction can create standing wave. So I use these:

> restart;
> with(plots):
> W1:=A*cos(omega*t-k*x);

> W2:=A*cos(omega*t+k*x);

> W:=W1+W2;

> SW:=(A,omega,k)->animate(plot,[{W1,W2,W},x=-4..4,y=-4..4,color=[red,green,blue],scaling=constrained],t=0..5,frames=10);

> display(SW(2,2*Pi,5),insequence);

It did work if SW is a function with one variable, now I need 3 variables (A,omega,k);

It said: "Plotting error, empty plot"

Please show me my mistake or an another method. Thank you

I have this matrix

 

uA := Matrix([[-w^2+x^2+y^2-z^2, -2*(w*y+x*z), 2*(-w*x+y*z)], [2*(-w*y+x*z), w^2+x^2-y^2-z^2, -2*(w*z+x*y)], [2*(w*x+y*z), 2*(-w*z+x*y), -w^2+x^2-y^2+z^2]])

and I would like to evaluate the variables like this

 

x = -x, y = -y, z = -z, w = -w

I tried this

Eval(uA, x = -x, y = -y, z = -z, w = -w)

but it didnt work.

 

Any suggestions??

 

Thank you so much

 

 

Hi!! i am working on assignment.

h:= x-> (x^17-x*sin(x^16))/x^49+exp(sqrt(x+8))*ln(abs((cos^4*(x)-5)));

 

i want to find the value of the h(10)

i use eval , but it comes out a function, not a solution.

please.help!!

I have been here before...  My head is full of cotton, as usual.

 

f := proc (t) 2*t^3+9*t^2-60*t+1 end proc;
deq:=diff(f(t),t);
df := t->deq;  ## this is most likely one of my problems.
plot(df(t),t=-10..10);
isneg := x -> if is(df(x) < 0) then df(x) else 0 end if;  ## and, another??
plot(isneg(t),t=-10..10);
Plt1:=plot(isneg(t),t=-10..10);
plots:-display(Plt1);
isneg(0.12017234);

The if statement is not fully evauated.

I am missing something.  What?

Tom Dean

Hi everyone,

I have a great problem with the evaluation of following definite integral

> restart;

> int((t-x)^2)/(1+2t+(1/2)t^2-ln(t^2+2t+2)t-ln(t^2+2t+2)+arctan(1+t)t^2+2arctan(1+t)t+ln(2)t+ln(2)-(pi/4)t^2-(pi/2)t)^2,t=0..x)

I have tried different classical commands but Maple doesn't give an answer. Probably, it's just a silly fault.

Does anyone knows how to solve it?

Thanks.

I have this (which finds each Fourier term of a sequence)

term := proc(lst,k::integer)
    local n;
    n := nops(lst);     
    seq(lst[m+1]*exp(-I * 2*Pi/n *(k*m)),m=0..n-1);
end proc;

Now I call it as

term([1,2,3],1);

and it returns

So it evaluated and convert the exp(-I * 2*Pi/n *(k*m)) terms. I wanted to keep these as is, so I can compare result with textbook. Then do simplify if I wanted to above output. 

I can do that if I use small pi instead of large Pi, like this

term := proc(lst,k::integer)
    local n;
    n := nops(lst);     
    seq(lst[m+1]*exp(-I * 2*pi/n *(k*m)),m=0..n-1);
end proc;

and now r:=term([1,2,3],1); return

Which is what I wanted, but with Pi instead of pi.  now how would I evaluate the above?

I tried to use subs to replace small pi with large Pi, but it does not work

subs(pi=Pi,r); #error

Then I tried eval, which worked

eval(r,pi=Pi);

So, I can use the above method.

My question is: Is the above a common way to handle such case? Is there another way to use Pi but at the same time prevent Maple from automatic simplification of the exp() terms?

 

 

 

 

Hi,

 

  I have the following code for using "PolynomialSystem" solve equations of polynomial

 

*********

with(SolveTools):

f:=PolynomialSystem({x+y-3, x^2+y^2-5}, {x, y}):

print(x,y);
print(f);
f[1];f[2];
a:=f[1][1];b:=f[1][2];
print(a,b);
c:=-evalf(a);d:=-evalf(b);

****************

 

The output is

***

x, y
{x = 2, y = 1}, {x = 1, y = 2}
{x = 2, y = 1}
{x = 1, y = 2}
x = 2
y = 1
x = 2, y = 1
-x = -2.
-y = -1.

***

From what I have seen, I cannot subtract the values of x and y as 2 and 1. Is there any way that I can get the values of solutions of variables, namely I can assign a variable "a" as 2, and the other variable "b" as 1?

 

Thank you very much!

 

 

 

 

Sorry for basic question, Maple newbie here and I could not find answer using google.

I understand in Maple one uses the back quote key (or rather the apostrophe, 0X27) to prevent one time evaluation of expression. Hence when writing

'sin(Pi)'; #this remain sin(Pi)
%; # now we get 0

But when I tried it on fraction, it did not hold it:

'16/4'; #maple replied with 4

This might indicate that the front end parser did this simplification before the main evaluator got hold of it, so it was too late?

Either way, how would one make Maple return 16/4 when the input is '16/4'?

Hi 

I'm having a problem with the statements inside a for-loop somehow being read in a different way than outside the loop. 

I've defined some functions earlier, and then I need to perform an integration using these functions, while I change one variable a little for each loop of the for-loop. 

The problem is that IN the for-loop, I get the same value from my integration for all loops. But when I execute the exsact same code OUTSIDE of the loop, I get the correct values, which are changing whenever i change the one variable. 

Here is the loop:

for i from 0 to 42 do

rotorshift := evalf[6](2*((1/180)* *Pi*((1/2)*Ø[gap]))/N[m]-1/2*(tau[p]-tau[s]));

PMmmf_func := x-> proc (x) if type(x-rotorshift, nonnegative) then if type(trunc((x-rotorshift)/tau[p]), odd) = true then -H[c]*l[m] else H[c]*l[m] end if else if type(trunc((x-rotorshift)/tau[p]), odd) = true then H[c]*l[m] else -H[c]*l[m] end if end if end proc

B[g] := proc (x) -> 1000*mu[0]*(PMmmf_func(x)+MMF_func(x))/d[eff, stator](x) end proc;

Flux(i+1) := (int(B[g](x), 0 .. tau[s])+int(B[g](x), 3*tau[s] .. 4*tau[s])+int(B[g](x), 6*tau[s] .. 7*tau[s])+int(B[g](x), 9*tau[s] .. 10*tau[s]))*10^(-3)*L[ro];

end do;

And for all the values in the "Flux" vector, I get the same value. But when I remove the loop, and change the value of manually, I get the correct (changing) values of flux!! 

Any ideas why this may be? This is really dricing me nuts. I've spent the beter part of the day on this, and I just can't seem to find a workaround, much less a reason for this behaviour.

many thanks!

I want to print 2+3= in the input and get exactly the same output.

And how can i do it in a program?

Is it possible to evaluate a function at multiple points described by an array or something of that sort and have Maple return the evaluations as an array. I need approximations of a function at various values of its argument so it would be nice to do it with a single command.

Thanks

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