@vv Thank you

@dharr Thanks a lot.

@dharr Thanks a lot. I have two questions:

1. what is 

2. 

ode1 := PDEtools:-dchange(tr, de1/(K*R), [t, x, y, a, b, c, q, m], simplify);
                            /    2                          \
           d           x(t) \x(t)  + (a - 1) x(t) - a + y(t)/
  ode1 := --- x(t) = - --------------------------------------
           dt                         x(t) + a               

ode2 := PDEtools:-dchange(tr, alpha*de2/(R^2*K), [t, x, y, a, b, c, q, m], simplify);
         d         
ode2 := --- y(t) = 
         dt        

  y(t) ((q (b - m) y(t) + b + c - m) x(t) + a (-m q y(t) + c - m))
  ----------------------------------------------------------------
                      (x(t) + a) (1 + q y(t))                     

These two are not as nicely organized as you. What to do? dchange1.mw

@mmcdara Thank you...It works

@rcorless 

Is there any process to get like this

resultant(A, a01*(a20*b20 - a30*b10) + a11*a20*b11, a20*b20 - a30*b10)

I tried with 

B := a20*b20 - a30*b10;
               resultant(A, a11*a20*b11 + B*a01, B);

But not works 

@vv After simplifying A there will be terms involving  sigma+x, sigma*x & I want to put a and b in that places

@vv It is just a polynomial. No square roots. 

I want to get the coeff x*sigma^2, coeff x^2*sigma etc. How to do that?

@Carl Love Is it possible to get the Taylor series by letting sqrt(epsilon)=x about (x=0,lambda2=0)?

If yes please suggest the steps.

@Carl Love Thanks a lot

@Joe Riel Thanks for the information Joe. 

@Kitonum 

What is

``

Please give me a link from where I can read about it...

@acer Thanks a lot

@Carl Love Yes I need the 2nd presentation that you have mentioned but separeted by comma. Like

h1,   h2,    h3,

h4,   h5,    h6

AA1, AA2, AA3,

AA4, AA4, AA6

@Carl Love Yes I need two different rows.

@Carl Love Now it is exactly that I want. Thanks a lot.