Hello,
the following command

collect(c4*dnub*kpbr*ksr*nur*nurdel + c4*dnur*kpbr*ksr*nub*nurdel, [nur, nub, dnur, dnub, nurdel, nubdel, dnurdel, dnubdel, c4], distributed)

returns

c4*dnub*kpbr*ksr*nur*nurdel + c4*dnur*kpbr*ksr*nub*nurdel

However, I am expecting it to return

c4*kpbr*ksr*(dnub*nur*nurdel+dnur*nub*nurdel)

Where is the error?
Thanks in advance

Hello,

Lets say I have an expression

f:=(a+b)*x1+(a^2+b^2)*(x1+x2^2)+c*(x2-x3)*a*b

and I have a list

p:=[a+b,a^2+b^2,c*b*a].

How can I get the coefficients of the element from p in f, ie,

cof=[x1,x1+x2^2, x2-x3].

such that cof[i] corresponds to p[i]?

Thanks in advance for your suggestions.

Hello,

I have the following expression

Ve*k21*ke*x1+Ve*k21*x1^2+k12*ke^2*x1[t]+2*k12*ke*x1*x1[t]+k12*x1^2*x1[t]+k21*ke
^2*x1[t]+2*k21*ke*x1*x1[t]+k21*x1^2*x1[t]+Ve*ke*x1[t]+ke^2*x1[t,t]+2*ke*x1*x1[t
,t]+x1^2*x1[t,t]

and I want to convert it to

x1[t,t]*(x1+ke)^2+(k12+k21)*x1[t]*(x1+ke)^2+Ve*x1[t]*ke+(k21*Ve)*x1*(x1+ke)

How can I do this opperation? This is just a simple example of a more general problem I am facing. Thanks in advance for your help