## 18 Reputation

19 years, 96 days

## a few integrals in Maple...

Maple

Trying a few integrals in Maple -- doesn't seem to handle them very well. Any workarounds please?

f1(p,b):= 1/(p^2 + b^2)^2 ;

f2(p,b):= exp(-p/b)^2;

T1pbm := Int(q*f1(q, b)*ln((p+q)^2+m^2), q = 0 .. infinity);

T2pbm := Int(q*f1(q, b)*ln((p-q)^2+m^2), q = 0 .. infinity);

with(IntegrationTools):

PT1 := evalf(Parts(T1pbm, q*f1(q, b), ln((p+q)^2+m^2)));

PT2 := evalf(Parts(T2pbm, q*f1(q, b), ln((p-q)^2+m^2)));

Ev := evalf(-pi*c*Int*(p*f1(p, b)*(PT1-PT2), p = 0 .. infinity))

## ordered product of creation and annihila...

Maple 16

Hello,

I am trying to find the product of three groups of creation and annihilation operators. After completing the input of the groups, Maple fails to give me the product of the operators (value of sigma^3) as shown below. What I need is for Maple to give me the ordered product of the three groups, but the "expand" command (lowercase 'e') fails to produce any output. Appreciate any help.

> with(Physics);
> Setup(mathematicalnotation = true);
print(`output redirected...`...

## basic input with x and xdot where (xdot...

Maple

How does one enter (and evaluate the following expression) in Maple

d/dt [ del(L)/del(xdot) ] = del(L) /del(x)

where "del" stands for the partial differential sign and "xdot" is the
simple derivative of x wrt t?

For example, I have L = 0.5*m*xdot^2 - mgx

Note that I understand f:=(x,xdot) -> 0.5.m.xdot^2 - m.g.x, but can't seem to make Maple realize that xdot = d/dt(x) within the partial derivative del(L)/del(xdot)

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