Greetings

I am left wondering why evalf as well as right clicking and selecting approximate both are in error.

Try 1/2*sqrt(109) and find a solution with 5 digits (english isnt my first language so the wording may not be correct).

If you calculate it as 1/2*sqrt(109.0) you correctly get 5.2202

However, if you use evalf(1/2*sqrt(109)) or 1/2*sqrt(109) then right click and approximate with 5 digits you incorrectly get 5.2200.

I assume this is because both incorrectly round to 5 digits on sqrt(109) before dividing by 2 - a common mistake for very inexperienced students but surely not something I would expect from Maple.

Please explain and better yet fix. Thanks.

i'm going to solve the two eq. and plot the answer point

i try to do two group but the first succeed the second get some wrong

the first i named 1 ,and second named 2 as below

the 1 plot the correct point that i want

Although the 2 solve eq too but it didn't plot the point on(-0.36,0.29),

the code of this two is same ,

anyone can help me?

1.mw

2.mw

Hello.

I am trying to extract all the coefficients of a linear equation by calling coeffs function.

I expected I receive the coefficients in the same order as in vars variable, but I was wrong. How to extract coefficients in the order I need?

Download test.mw

Is there a way to open a classic worksheet in macintosh, even running windows through a virtual machine?

cilrcle.mw

i want to plot a circle which is centered at(0,0),and the radius is the length of Point2 and origin

but it shows some error,how could i do to solve this

cilrcle.mw

i want to plot a circle with that centered at (0,0),and the radius is the length of Point2 and orgin

but it shows the error

how could i do to solve this

color.mw

how can i do if i  want to change the color of point1 which is rotated from point2

i want to make point2 red , and point1 is black , but the point1 is still  red

anyone can help me? thx

Hello People in mapleprimes,

I want to know how to factor the denominator of the first term in the right hand side, using commands not clickable math.

And, I know applyop can be used in this case, but I want to know is other ways than using applyop. 

-tau*alpha*sigma*omega*(tau-omega^(-sigma))/(s*L*(1-gamma-tau^2+tau^2*gamma))

-(sigma*alpha)/s*(1-tau*omega^sigma)/(omega^(sigma-1)*(1-gamma)*L*(1/tau-tau));

Thanks in advance.

taro

for example i want to save the Square root of 2 to 1000000 decimal place to an ascii text file ...

i used the writeto command after evalf[100](sqrt(2)) for but it contains line breaks and \ character in output !

but i only need the pure continues 1000000 digits !

please guide me on this simple request ?

Hi Maple friends.

If I have a table of values, how can Maple provide the function?

For example:

x=10,15,20,25,30,35,40

y=2.01,4.87,6.50,9.875,14.00,18.90,24.40

How can Maple find out the y function with respect to x? 

Thanks in advance.

Hi,

I'm trying to make a piecewise function that will have period 12. That is, it repeats every 12 units across the x-axis.

I managed to do one cycle successfully with

plot(piecewise(0<=t and t<2, 4,2<=t and t<12,0), t=0..13);

But I'm not sure how to do it periodically. I thought about using modular arithmetic in the conditions and setting up something like

H(t)=piecewise(0<=modp1(f(t),12) and modp1(f(t),12)<2, 4,2<=modp1(f(t),12) and modp1(f(t),12)<12,0);

but this clearly doesn't work.

Some direction or advice would be appreciated. Thanks!

I would like to pay attention to a series of applications by Samir Khan
http://www.maplesoft.com/applications/view.aspx?SID=153600
http://www.maplesoft.com/applications/view.aspx?SID=153599
http://www.maplesoft.com/applications/view.aspx?SID=153596
http://www.maplesoft.com/applications/view.aspx?SID=153598
My congratulations to the author on his work well done. New capacities of Global Optimization Toolbox are spectacular. For example, in the first application  an optimization
problem in 101 variables under 5050 nonlinear  constraints
(other than 202 bounds) is solved.
I think it requires a very powerful comp and much time.
I tried that  problem for n=20 with the good old DirectSearch
on my comp (4 GB RAM, Pentium Dual-Core CPU E5700@3GHz) by

soln2 := DirectSearch:-GlobalSearch(rc, {cons1, cons2, rc >= 0,
seq(`and`(vars[i] >= -70, vars[i] <= 70), i = 1 .. 2*n), rc <= 70},
variables = vars, method = quadratic, number = 140, solutions = 1,
evaluationlimit = 20000)

and obtained not so bad rc=69.9609360106765 (whereas www.packomania.com gives rc=58.4005674790451137175957) in about one hour.

Packing_by_DS.mw
For n=50 the memory of my comp cannot allocate calculations or the obtained result by the Search command is far away from the one in packomania.

Hi i have trouble with this equation to solve with maple please help me

with boundary condition :

how i solve above equation with maple?( there is function to solve this equation in maple ?

email :

sattar.dogonchi@yahoo.com

Hi There

I'm getting started with maple and facing a doubt about using subs, somehow it does not seem to work, this is my expression:

> restart;
> theta := omega*t-k*x;
                                omega t - k x
> phi[1] := -(1/2)*H*c*cosh(k*(z+h))*sin(theta)/sinh(k*h);
                   H c cosh(k (z + h)) sin(-omega t + k x)
                   ---------------------------------------
                                 2 sinh(k h)              
> diff(phi[1], t, t);
                                                             2
                H c cosh(k (z + h)) sin(-omega t + k x) omega
              - ----------------------------------------------
                                 2 sinh(k h)                  
> td := simplify(subs(z = 0, %));
                                                          2
                   H c cosh(k h) sin(-omega t + k x) omega
                 - ----------------------------------------
                                 2 sinh(k h)               
> simplify(subs(cosh(k*h)/sinh(k*h) = 1/tanh(k*h), %));
                                                          2
                   H c cosh(k h) sin(-omega t + k x) omega
                 - ----------------------------------------
                                 2 sinh(k h)               
I cannot subs cosh/sinh = tanh. I would like to know why.

Any tips? Thank you

Dear friends:

I have a long expression having a/some RootOf(something..) inside it. 

Any way to get just that "something..", i.e., the argument of RootOf() from that expression?

Thank you very much.

César Lozada