Output Answer by solve

Hello

In the output the values give this result. I want to get the values:

syms X1 X2 X3 X4
eq=[X1^2+X2^2==1949.947, (X1*X3)+(X2*X4)==-28.338, eq3=(X3*X1)+(X4*X2)==-28.338, eq4=X3^2=X4^2-81.892]
[x1,x2,x3,x4]=solve([eq],[X1,X2,X3,X4])

x1 =

Empty sym: 0-by-1

x2 =

Empty sym: 0-by-1

x3 =

Empty sym: 0-by-1

x4 =

Empty sym: 0-by-1

Thank you for helping me

[Walter Roberson]

syms X1 X2 X3 X4
eq=[X1^2+X2^2==1949.947, (X1*X3)+(X2*X4)==-28.338, eq3=(X3*X1)+(X4*X2)==-28.338, eq4=X3^2=X4^2-81.892]
[x1,x2,x3,x4]=solve([eq],[X1,X2,X3,X4])

You have eq3= and eq4= in the middle of the []. These days that is equivalent to

eq = [ X1^2+X2^2==1949.947,... 
(X1*X3)+(X2*X4)==-28.338, ...
'eq3', ...
(X3*X1)+(X4*X2)==-28.338, ...
'eq4', ... 
X3^2=X4^2-81.892]
[x1,x2,x3,x4]=solve([eq],[X1,X2,X3,X4])

[Farshid R]

Thank you .According to document version 2018b I would do ,however,it answers these . your code make error in matlab for me. I don ot know really why.

I read document solve.

Is there another way?

[Torsten]

Is there another way?

Yes: copy KSSV's solution.

Maybe he will be so kind to replace the numbers by symbolic variables so that you can play with the right-hand side of your equations.

[Farshid R]

Thank you so much.

[Walter Roberson]

Your second and third equations are the same. There would not be a unique solution .

Answer 1

[KSSV]

syms X1 X2 X3 X4
eq1 = X1^2+X2^2==1949.947 ;
eq2 = (X1*X3)+(X2*X4)==-28.338;
eq3 = (X3*X1)+(X4*X2)==-28.338;
eq4 = X3^2==X4^2-81.892 ;
eqs = [eq1, eq2, eq3, eq4] ;

s=solve(eqs,[X1,X2,X3,X4]) ;
s.X1

ans = 

s.X2

ans = 

[Farshid R]

Thank you

But when I execute this code as well as your code, it gives me this output. What do you think why shows these answers?

Empty sym: 0-by-1

[KSSV]

What version you are using?

version

ans = '9.12.0.1952421 (R2022a) Update 1'

[Farshid R]

I use V.2018b

[KSSV]

Read the documentation up there. The problem is due to version.

[Farshid R]

Many thanks dear