Hi. I wrote a command for finding second derivative.

#secondderiv test of f(x,y)
f:=x^2+2*x*y+2*y^3:
Gradient(f,[x,y]);
soln:=solve(Equate(Gradient(f,[x,y]),<0,0>));
H:=hessian(f,[x,y]);
seq([subs(soln[k],eval(H)),det(subs(soln[k],eval(H)))],k=1..nops(op(soln)))

Everything runs fine ... except if I change the function f to
f:=x^2+2*x*y+2*y^2
Then I get error :
Error, invalid input: nops expects 1 argument, but received 2

I sort of understand the error, when there is a single solution
{x=0,y=0} , then the op removes the parentheses to get x=0, y=0
which is now two arguments, and nops requires one argument.
I tried to use  nops(op({soln} ) , but that is not the correct approach
since it overcounts. Also it throws an error if change back f to the original expression.

Hello,

I have an implicit function and I have plotted the graph of the same in maple 18 worksheet. Now I would like to export the data of the same graph into an excel file so that I can use it further. Kindly provide the solution and if some kind of example is provided I'll be highly grateful to you.

Thanks in advance

when i evaluate integration and my result s are HFloat what does it mean ?

how to avoid it ?

and how to distribute integration when the expand command doesnt work?
 

Can someone please explain to me why i would be getting the error that i do not have permission to read a text file, when i can clearly open that text file under the same account.

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Hi

I need to express some discrete functions with domain in the natural numbers.

Is there a command like the 'AllSolutions' which is used for int?

As an example, how we can express all possible values of first derivative of chebyshev polynomial for various orders in terms of a piecewise function at origin ?

The following commands do not return a suitable answer, in this case!

f:=diff(ChebyshevT(n, r), r):

g:=simplify(eval(f, r = 0), symbolic) assuming(n::integer);

`assuming`([convert(g, piecewise, n)], [n::integer]);

Hello people in mapleprimes,

I installed maple 2018 Japanese version.
And, with solve(x^2-1,x), its solution is expressed as _EXPSEQ(1, -1)

I know this expression is an internal represantation.
How can I have maple answer as 1, -1?

Thanks in advance.

Addition: my pc is mac osx 10.13.6.
 

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why the Sum() comand  give me error with single processing comand

Hello again, folks!!!

Can you help me in this matter?

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Hello,

I'm trying to solve  inverse trigonometric equation:

EQ := sqrt(3)*arctan(x/sqrt(3))-arctan(x) = 1;

sol := solve(EQ, {x});

#sol := {x = sqrt(3)*tan(RootOf(-tan(sqrt(3)*_Z-1)*sqrt(3)+3*tan(_Z)))}

evalf(sol);

#{x = 13.24164497} OK. one Real solution.

sol2 := evalf(allvalues(sol));

#sol2 := {x = -.1141310781-1.108044977*I}, {x = -.1141310781+1.108044977*I}, # {x = 1.142681884}, {x #= -2.379974990}, {x = 13.24164497}

Check:

seq(evalf(eval(EQ, sol2[k])), k = 1 .. nops([sol2]));

#.99999999991340592650+1.61960960*10^(-11)*I = 1., .99999999991340592650-#1.61960960*10^(-11)*I = 1., .15821278548775934290 = 1., -.4580182246463005988 = 1., #.9999999996233630663 = 1.

1.Can someone explain to me where did Maple find these Additional roots like: {x = 1.142681884}, {x = -2.379974990}?

2.It's a Bug or normal behavior ?

I have three questions

1:= If I have summation over i from 0 to 100 how do I prevent maple from unpacking the sum and set it like it is?

2:= Does the comand evalf give me an imaginary evaluation if we apply it in a sum and how do I avoid that?

3:= For infinite sum, Maple evaluates it with term hyper geometry and can't after that evaluate the diffrentation how do I prevent that?

Good morning, I'm trying to solve this very simple problem : plot a graph starting from the origin. The problem is that the x_axis is located at the lower value of my function, but i want it to go through the point (0,0). Let's see this example:

plot(piecewise( x<5, 100, x>5,200), x=0..10); As you can se the X-axis passes through y=100.

Now with this option I obtain:

plot(piecewise( x<5, 100, x>5,200), x=0..10, y=0..200); 

The problem is taht I need to specify the upper bound of the range for each function (200). Is there an automatic way? Any help is appreciated.

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Hi.

I want to use canonical analysis or any other method to get vlaue of X1,X2.

How do I get  x 1, x 2 value?

please help!!

Hi.

Is possible to pdsolve these equations via maple.

Functions f1(x) and f2(x) and g(x) are aviable and only  phi and p1(x,z) and p3(x,z) are unknown.

I want to determine phi and p1(x,z) and p3(x,z).

 Also other parameter suvh as h-alpha-beta-beta1 -beta3 and L,..  are aviable and are not unknown.

Thanks

After calculations the integral contains infinity. what it resembles? Is it correct  answer?  Please check the file maple
 

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1.mw maple1.pdf