John Eric

Dr. John Eric

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9 years, 67 days

MaplePrimes Activity


These are questions asked by John Eric

Hello, I have a program which works fine in maple but get stuck when I use it in maple 2021 please I need your help thank you in advance

mpprime.mw

Hello, 

I'm trying to calculate the convolution of the radiation forve in the time domain. I need to do a state space representation of a function K(t), where :

t=[0; 1; 2; 3];

k=[0.1; 0.2; 0.3; 0.4];

If you could help me with finding the appropriate command that give the matrix A, B C and D

just a remarque that in matlab used imp2ss (based on the Hankel SVD method)

thanks

Hello everyone,

Please how can I caluclate an integrale based on data set (Q) usiing any integral method

thanks


 

restart:

NULL

NULL

NULL

Q := [21521.7, 11966.6, 7859.78, 7947.54, 9667.45, 10206.8, 10934.0, 10925.0, 11151.5, 10964.6, 11009.0, 11087.0, 11164.3, 11215.7, 11272.7, 11319.0, 11354.6, 11386.2, 11413.5, 11436.3, 11456.0, 11473.2, 11488.2, 11501.1, 11512.7, 11523.0, 11532.2, 11540.3, 11547.7, 11554.3, 11560.3, 11565.8, 11570.7, 11575.3, 11579.4, 11583.2, 11586.7, 11590.0, 11592.9, 11595.7, 11598.2, 11600.6]

[21521.7, 11966.6, 7859.78, 7947.54, 9667.45, 10206.8, 10934.0, 10925.0, 11151.5, 10964.6, 11009.0, 11087.0, 11164.3, 11215.7, 11272.7, 11319.0, 11354.6, 11386.2, 11413.5, 11436.3, 11456.0, 11473.2, 11488.2, 11501.1, 11512.7, 11523.0, 11532.2, 11540.3, 11547.7, 11554.3, 11560.3, 11565.8, 11570.7, 11575.3, 11579.4, 11583.2, 11586.7, 11590.0, 11592.9, 11595.7, 11598.2, 11600.6]

(1)

``

NULL


 

Download simpson.mw

hello everyone,

please I need our help to find the eigenvalues (m) of this equation (eq)

thank you 

eq.mw
 

``

restart

with(LinearAlgebra):

NULL

Digits := 5:

``

``

eq := exp(-m*xi)*(exp((1/4)*sqrt(-m)*r*(r-1))*(1+(7/20)*sqrt(m)*r+((49/800)*m-(1/4)*sqrt(m))*r^2)*r^I+exp((1/4)*sqrt(-m)*r*(r-1))*(1+(7/20)*sqrt(m)*r+((49/800)*m-(1/4)*sqrt(m))*r^2)*r^I*cos(theta)+r^I*sin(5*theta))

exp(-m*xi)*(exp((1/4)*(-m)^(1/2)*r*(r-1))*(1+(7/20)*m^(1/2)*r+((49/800)*m-(1/4)*m^(1/2))*r^2)*r^I+exp((1/4)*(-m)^(1/2)*r*(r-1))*(1+(7/20)*m^(1/2)*r+((49/800)*m-(1/4)*m^(1/2))*r^2)*r^I*cos(theta)+r^I*sin(5*theta))

(1)

``


 

Download eq.mw

 

Hello, would you please help with this problem

 I need to solve the system using polynomial coefficients

thank you 


 

restart

``

eq1 := diff(A(r), r, r)+(diff(A(r), r))/r+A(r)/r^2-a*r*A(r)+b*r^2*f*B(r)

diff(diff(A(r), r), r)+(diff(A(r), r))/r+A(r)/r^2-a*r*A(r)+b*r^2*f*B(r)

(1)

eq2 := diff(B(r), r, r)+(diff(B(r), r))/r+B(r)/r^2-c*r*A(r)+d*r^2*B(r)

diff(diff(B(r), r), r)+(diff(B(r), r))/r+B(r)/r^2-c*r*A(r)+d*r^2*B(r)

(2)

``

``

dsolve({eq1, eq2}, {A(r), B(r)});

{A(r) = DESol({-(-b*c*f*r^7+a*d*r^7-d*r^4+2*a*r^3-17)*_Y(r)/r^4-(-d*r^5-a*r^4-3*r)*(diff(_Y(r), r))/r^4-(-d*r^6+a*r^5-r^2)*(diff(diff(_Y(r), r), r))/r^4-2*(diff(diff(diff(_Y(r), r), r), r))/r+diff(diff(diff(diff(_Y(r), r), r), r), r)}, {_Y(r)}), B(r) = (a*r^3*A(r)-(diff(diff(A(r), r), r))*r^2-(diff(A(r), r))*r-A(r))/(b*f*r^4)}

(3)

dsolve({eq1, eq2}, {A(r), B(r)}, 'formal_series', 'coeffs' = 'polynomial')

Error, (in dsolve/FORMALSERIES) the first argument must be a homogeneous linear ode with polynomial coefficients

 

``

``

``


 

Download dsolve.mwdsolve.mw

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