emersondiaz

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MaplePrimes Activity


These are questions asked by emersondiaz

Good day people, here just asking for your help please.

I am trying to do a taylor serie of a function but I recieved this error:

Error, (in Typesetting:-NeedsBrace) invalid input: the 1st argument to pointto is not a valid pointer handle

The aim of this is get the series to do its integration.

Thank you a lot for your responses.

maple_primes_question.mw

Good day to all of you. 

I am working with a differential equation, got a first approximation setting all the constants equal to 1. But at the time to use the real values there appears the error numeric exception: division by zero.

I'll thanks any advice.

best regards

division_by_zero.mw

Good day to all the members who read this question.
I ask for your help to find the right way to solve this two differential equations (is attached the file). Used the common code "dsolve" but is not working on this problem. Doesn't matter if the solution is numeric or algebraic.
I will thaks a lot your kind help.
Best regards to all of you

DIFFERENTIAL_EQUATION.mw

restart

with(PDEtools)

First Part

The differential equation to solve:

(Delta*LinearAlgebra:-Transpose(D[1/2])*D__0-I*`μ__e`*D__0/(lambda+I*`μ__e`*r)-2*(`μ__e`^2*r^2+lambda^2))*R(r)

Definitions

D__n = `∂__r`+I*omega(a^2+r^2)/Delta+I*a*m/Delta+2*n*(r-M)/Delta

LinearAlgebra:-Transpose(D[n]) = `∂__r`-I*omega(a^2+r^2)/Delta-I*a*m/Delta+2*n*(r-M)/Delta

a := 1; M := 1; omega := 1; m := 1; `μ__e` := 1; lambda := 1

Delta := -2*M*r+a^2+r^2

I divided the differential equation in 3 parts (A, B, C).

A := (-I*omega(a^2+r^2)-I*a*m+r-M)*(diff(R(r), r)+I*omega(a^2+r^2)*R(r)/Delta+I*a*m*R(r)/Delta)+Delta*(diff(R(r), r, r))+I*omega(a^2+r^2)*(diff(R(r), r))+I*a*m*(diff(R(r), r))

B := -I*`μ__e`*(diff(R(r), r)+I*omega(a^2+r^2)*R(r)/Delta+I*a*m*R(r)/Delta)/(lambda+I*`μ__e`*r)

C := -(2*(`μ__e`^2*r^2+lambda^2))*R(r)

DE := A+B+C

E := dsolve(DE)

R(r) = DESol({diff(diff(_Y(r), r), r)-(1-r+I/(1+I*r))*(diff(_Y(r), r))/(r^2-2*r+1)-(-(2*I)*((-1-2*I)+r)/(r^2-2*r+1)-2/((1+I*r)*(r^2-2*r+1))+2*r^2+2)*_Y(r)/(r^2-2*r+1)}, {_Y(r)})

(1)

dsolve({DE, DE(0) = 1}, numeric, range = 0 .. 20)

Error, (in dsolve/numeric/type_check) insufficient initial/boundary value information for procedure defined problem

 

Second Part

The differential equation to solve:

[`#msub(mi("L",fontweight = "bold"),mfrac(mn("1",fontweight = "bold"),mn("2",fontweight = "bold"),linethickness = "1"))`*LinearAlgebra:-Transpose(L[1/2])+a*`μ__e`*sin(theta)*LinearAlgebra:-Transpose(L[1/2])/(lambda+a*`μ__e`*cos(theta))+2*(lambda^2+a^2*`μ__e`*cos(theta)^2)]*S(theta) = 0

Definitions:

L__n = a*omega*`sinθ`+m*`cosecθ`+n*`cotθ`+`∂__θ`

LinearAlgebra:-Transpose(L[n]) = -a*omega*`sinθ`-m*`cosecθ`+n*`cotθ`+`∂__θ`

Also I divided the differential equation in 3 parts (A, B, C).

F := (omega*a*sin(theta)+m/sin(theta)+1/(2*tan(theta)))(diff(S(theta), theta)-omega*a*sin(theta)*S(theta)-m*S(theta)/sin(theta)+S(theta)/(2*tan(theta)))+diff(S(theta), theta, theta)-omega*a*sin(theta)*(diff(S(theta), theta))-m*(diff(S(theta), theta))/sin(theta)+(diff(S(theta), theta))/(2*tan(theta))

G := a*`μ__e`*sin(theta)*(diff(S(theta), theta)-omega*a*sin(theta)*S(theta)-m*S(theta)/sin(theta)+S(theta)/(2*tan(theta)))/(lambda+a*`μ__e`*cos(theta))

H := (2*(lambda^2+a^2*`μ__e`*cos(theta)^2))*S(theta)

DF := F+G+H

dsolve(DF)

dsolve({DF, DF(0) = 1}, numeric, range = 0 .. 20)

Error, (in dsolve/numeric/type_check) insufficient initial/boundary value information for procedure defined problem

 

NULL

Download DIFFERENTIAL_EQUATION.mw

Good Day to all of you.

I am using the function NLPSolve to optimize a function and get its independent variable mínimum value. The problem is that is imposible to plot that Numbers because of the output way. Is like [5.02, [x=0.02]] and is imposible for my to graph. 
The file is attached and also the code of someone tha did it in matlab, is exacly the same result i want to obtain.

I would be really thanks if someone can help me.

Best regards

4.6.mw

matlab_solution.pdf

Hello to everyone

I have tried to solve This integral and untill here maple is unable to do it.

-2/3 + int(sqrt(x)/(exp((x-y)/tau ) + 1), x=0..infinity);

any idea? 
And thanks for your support

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