# Solve vs Reduce and use of parameters

i'm new in the world of mathematica. i have a simple problem : i want to find a solution of a system of equations. The problems are:

1) Is it better to use Solve or Reduce (for this kind of situation)?

2) I've problem with the (known) parameters of these equations ( f_1 , f_2).

Let's see the matter:

the code is ( here there is a screen more clear because the subscripts make trouble):

[code]

Reduce[{(1/Sqrt[V (Subscript[Z, 1] *Subscript[Z, 2]*Subscript[Z, 3] -
V*MU)]) == (Subscript[f, 1]*Subscript[f, 2])^(-1/2),Sqrt[(Subscript[Z, 1] *Subscript[Z, 2]*Subscript[Z, 3] - V*MU)/
V] Subscript[Z, 1]^-1 == (Subscript[f, 1]/Subscript[f, 2])^(
1/2), Sqrt[(Subscript[Z, 1] *Subscript[Z, 2]*Subscript[Z, 3] -
V*MU)/V] Subscript[Z,
2]^-1 == (Subscript[f, 2]/Subscript[f, 1])^(1/2),
Sqrt[(Subscript[Z, 1] *Subscript[Z, 2]*Subscript[Z, 3] - V*MU)/
V] Subscript[Z, 3]^-1 == (Subscript[f, 1]*Subscript[f, 2])^(
1/2), ((Subscript[Z, 1] *Subscript[Z, 2]*Subscript[Z, 3] - V*MU)^(
3/2)/(V^(3/2)*Subscript[Z, 1] *Subscript[Z, 2]*Subscript[Z,
3]) ) == (Subscript[f, 1]*Subscript[f, 2])^(1/2), MU == 0}, {V,
Subscript[Z, 1] , Subscript[Z, 2], Subscript[Z, 3], MU}, Reals]

• I have fixed the parameters to be positive but i obtain two conditional expressions associated to two values.

• If you see it finds the value of Z_1 but it doesn't substitute its value into Z_3.

Thank you.

• How much of this question is covered by: Solve vs Reduce? – Kuba Oct 2 '18 at 7:34
• The subscripts will make debugging harder; reserve them only for display purposes. – J. M.'s technical difficulties Oct 2 '18 at 7:52
• @Kuba I have written in the problem list if for this kind of situation is better Reduce or solve – Mordin Solus Oct 3 '18 at 13:25
• @J.M.issomewhatokay. Before the stuff of the code there is the screeshot of the code which is the link called "code". – Mordin Solus Oct 3 '18 at 13:26
• As I already said: the subscripts certainly look pretty, but they will make algebraic manipulation a pain. Regarding your use of MatrixForm[], see this. – J. M.'s technical difficulties Oct 3 '18 at 13:28