9 years, 30 days

## repated summetion...

Maple

How i can i write the code for the last equation which includes summations and one product in the picture? tnx for the help

## factor differential operators...

Maple

i have two equations;i.g eq1 and eq2. i want to factor psi(x,t) in eq2 using linear differential operators and substitute it in equation 1. could anyone help?

 > restart:with(DEtools):
 > eq1:=E*D(II)(x)*D[1](psi)(x,t)+E*II(x)*(D[1]@@2)(psi)(x,t)-G*A(x)*psi(x,t)+G*A(x)*D[1](v)(x,t)
 (1)
 > convert(eq1,diff)
 (2)
 > eq2:=-(G*D[1](A)(x)*psi(x,t)+G*A(x)*D[1](psi)(x,t))+(G*D[1](A)(x)*v(x,t))+G*A(x)*(D[1]@@2)(v)(x,t)-m(x)/G*D[2](v)(x,t)
 (3)
 > convert(%,diff)
 (4)
 > isolate(convert(eq2,diff),psi)
 (5)
 > eval(eq1,psi(x,t)=rhs((isolate(eq2,psi))(x,t))):convert(%,diff)
 (6)
 >
 >
 >

## pdsolve with piecewise boundary conditio...

Maple

I have a question? from the link: https://www.maplesoft.com/applications/view.aspx?SID=5084&view=html

How can we solve equation 2.1 to achieve solution 3.1 with boundary conditions explained in section " 1) Gaussian solution " ?
is this possible with maple?

## plot output of an integral ...

Maple 2018

how this integration can be computed and plotted? tnx in advance

 > restart:Digits:=20:
 > T := 10^(-6); delta := 10; m := 1; alpha:= 75/10; v := 65; mu := 8;
 (1)
 > z := sqrt((omega^2 - 4*m^2)/alpha^2 - v^2/alpha^2*(4 *delta/alpha*tan(theta)^2 - v^4/alpha^4*tan(theta)^4))
 (2)
 > a := sec(theta)/sqrt(2)*sqrt((2 *delta)/alpha - v^2/alpha^2*tan(theta)^2 + z)
 (3)
 > f1 := 1/(exp(( omega/2 - mu)/T) + 1); f2 := 1/(exp((- (omega/2) - mu)/T) + 1);
 (4)
 > A1 := evalf(-(f1 - f2)*abs(omega/(4*a*alpha*cos(theta)^2*(-delta+ a^2 *alpha* cos(theta)^2) + 2*a*v^2*sin(theta)^2 + 1/10000)))
 (5)
 > b := sec(theta)/sqrt(2)*sqrt((2*delta)/alpha - v^2/alpha^2*tan(theta)^2 - z)
 (6)
 > f3 := 1/(exp(( omega/2 - mu)/T) + 1); f4 := 1/(exp((- (omega/2) - mu)/T) + 1);
 (7)
 > A2 := evalf(-(f3 - f2)*abs(omega/(4*b*alpha*cos(theta)^2*(-delta+ b^2 *alpha* cos(theta)^2) + 2*b*v^2*sin(theta)^2 + 1/10000)))
 (8)
 > plot(int(A1+A2,theta=0..2*Pi),omega=0..50);
 >

## sort an expression with order of a symbo...

Maple

How can this expression sorted in order of the symbol "y"? I want the terms with y locate at the beginnig.

 > restart:
 > f:=x^2+x^y+1-z
 (1)
 >