Hi! I have a new question. How can I integrate a function like:      S := 1/H(z)   ?

I wrote it as:

R := int(S,H = 'Y(z)', z=0..10);

but I got an error. What do you suggest to do this integral? Also, if I want to solve it as an undefined integral what should I do?

thanks. 

Hi! I have a new question. How can I integrate a function like:      S := 1/H(z)   ?

I wrote it as:

R := int(S,H = 'Y(z)', z=0..10);

but I got an error. What do you suggest to do this integral? Also, if I want to solve it as an undefined integral what should I do?

thanks. 

@DuncanA Hi! sorry, but there is a new problem. Now, I want to sort these data with respect to the third column(I mean "alpha") from min value to max value. I need the minimum value of alpha and also the "m" and "n" related to it. In another word, I want maple to show me, that row where includes the minimum value of alpha and "m" and "n" related to it. thanks for your help.  

@DuncanA Hi! sorry, but there is a new problem. Now, I want to sort these data with respect to the third column(I mean "alpha") from min value to max value. I need the minimum value of alpha and also the "m" and "n" related to it. In another word, I want maple to show me, that row where includes the minimum value of alpha and "m" and "n" related to it. thanks for your help.  

@DuncanA Hi! Thanks a lot! Your help was very useful for me. If I'll hava a new problem I'll write it for you.

@DuncanA Hi! Thanks a lot! Your help was very useful for me. If I'll hava a new problem I'll write it for you.

@DuncanA thanks, but I want to write "m", "n" and "alpha", in those three columns in a new file(a dat file). I've done it before but I don't want the sign " , " is in this dat file. I just want three columns of numbers.

@DuncanA thanks, but I want to write "m", "n" and "alpha", in those three columns in a new file(a dat file). I've done it before but I don't want the sign " , " is in this dat file. I just want three columns of numbers.

Thank you very much!

I corrected my program. Now I have a new question. How can I print my results in a table with 3 columns, first shows "m", second "n" and the third one "alpha"?

Thank you very much!

I corrected my program. Now I have a new question. How can I print my results in a table with 3 columns, first shows "m", second "n" and the third one "alpha"?

@Preben Alsholm Hello my friend!

I'm very thank you for your previous helps. Now, I have a new question related to my previous program. I want to solve numerically a differential equation where "H" exists in it:

D(L)(z) =( L(z)/(1+z) )+( (1+z)/H );

where "L" is a function of "z", like "H"(if you remember).

I tried:

p := dsolve({D(L)(z) =( L(z)/(1+z) )+( (1+z)/H ), H='Y(z)', L(0)=0}, type=numeric, range=0..5);

odeplot(p);

but it doesn't work. What should I do?

@Preben Alsholm Hello my friend!

I'm very thank you for your previous helps. Now, I have a new question related to my previous program. I want to solve numerically a differential equation where "H" exists in it:

D(L)(z) =( L(z)/(1+z) )+( (1+z)/H );

where "L" is a function of "z", like "H"(if you remember).

I tried:

p := dsolve({D(L)(z) =( L(z)/(1+z) )+( (1+z)/H ), H='Y(z)', L(0)=0}, type=numeric, range=0..5);

odeplot(p);

but it doesn't work. What should I do?

@Preben Alsholm Thank you very much. That's great. See you later!

@Preben Alsholm Thank you very much. That's great. See you later!

@Preben Alsholm O.K., I write whole my work for you:

restart:

with(plots, implicitplot):

eq := proc (z) options operator, arrow; (H^2+(-1)*.27*(1+z)^3-(1/20000)*(1+z)^4)/(H^2)^.1 = .7299500000 end proc;

Y := proc (z) options operator, arrow; fsolve(eq(z), H) end proc;

plot(Y, -10 .. 10, -10 .. 10);

Here is where I have the line below the x-axis. Tough I can write:

plots:-implicitplot(eq(z), z = -10 .. 10, H = -10 .. 10, grid = [150, 150]);

and obtain a more complete graph which has a line above the axis too. Then, for obtaining "diff(H(z), z)" I can write either:

plot(fdiff(Y, [1], z), z = -2 .. 2, caption = "The derivative of y using fdiff on Y");

or:

yp := implicitdiff(eq(z), H, z);

plot(eval(yp, H = 'Y(z)'), z = -3 .. 2, caption = "The derivative of y using implicitdiff and Y");

but remember in both the above procedures we have used "Y" and I think the one above has not considered in plotting  "diff(H(z), z)". Also, if now I want to plot a new function like: "w(z) :=( (1+z)*diff(H(z), z))/H(z)" I should write:

plot(eval((1+z)*yp/H, H = 'Y(z)'), z = -1 .. 5, view = -3 .. 3, caption = "The derivative of y using implicitdiff and Y");

In here, we are using "Y" which has only one below and doesn't know the one above and also "yp" where I think may not be complete(because to obtain it we have used "Y", as well).

sorry for this long message and thank you again!