I am trying to use Mathematica to diagonalize an array, but the solution contains the `root()`

function, instead of the answer resolved. Can I & # 39; force & # 39; Mathematica to solve the root function?

Copy Code:

```
y0 = KroneckerProduct(PauliMatrix(3), IdentityMatrix(2));
y1 = KroneckerProduct(I PauliMatrix(2), PauliMatrix(1));
y2 = KroneckerProduct(I PauliMatrix(2), PauliMatrix(2));
y3 = KroneckerProduct(I PauliMatrix(2), PauliMatrix(3));
o01 = 1/2 (y0.y1 - y1.y0); o01 // MatrixForm;
o02 = 1/2 (y0.y2 - y2.y0); o02 // MatrixForm;
o03 = 1/2 (y0.y3 - y3.y0); o03 // MatrixForm;
o12 = 1/2 (y1.y2 - y2.y1); o12 // MatrixForm;
o31 = 1/2 (y3.y1 - y1.y3); o31 // MatrixForm;
o23 = 1/2 (y2.y3 - y3.y2); o23 // MatrixForm;
y5 = I y0.y1.y2.y3 ;
v0 = y5.y0; v0 // MatrixForm;
v1 = y5.y1; v1 // MatrixForm;
v2 = y5.y2; v2 // MatrixForm;
v3 = y5.y3; v3 // MatrixForm;
y5 // MatrixForm;
M2 = Ex o01 + Ey o02 + Ez o03 + Bz o12 + By o31 + Bx o23 + X0 y0 +
X1 y1 + X2 y2 + X3 y3 + V0 v0 + V1 v1 + V2 v2 +
V3 v3; M2 // MatrixForm
DiagonalMatrix(Eigenvalues(M2)) // MatrixForm
```

The result below is one of the four own values of the matrix produced by `DiagonalMatrix(Eigenvalues(M2))`

. It contains the root function instead of the explicit solution. Why doesn't Mathematica solve the root function?

```
Root(Bx^4 + 2 Bx^2 By^2 + By^4 + 2 Bx^2 Bz^2 + 2 By^2 Bz^2 + Bz^4 +
2 Bx^2 Ex^2 - 2 By^2 Ex^2 - 2 Bz^2 Ex^2 + Ex^4 + 8 Bx By Ex Ey -
2 Bx^2 Ey^2 + 2 By^2 Ey^2 - 2 Bz^2 Ey^2 + 2 Ex^2 Ey^2 + Ey^4 +
8 Bx Bz Ex Ez + 8 By Bz Ey Ez - 2 Bx^2 Ez^2 - 2 By^2 Ez^2 +
2 Bz^2 Ez^2 + 2 Ex^2 Ez^2 + 2 Ey^2 Ez^2 + Ez^4 - 2 Bx^2 V0^2 -
2 By^2 V0^2 - 2 Bz^2 V0^2 - 2 Ex^2 V0^2 - 2 Ey^2 V0^2 -
2 Ez^2 V0^2 + V0^4 + 8 Bz Ey V0 V1 - 8 By Ez V0 V1 + 2 Bx^2 V1^2 -
2 By^2 V1^2 - 2 Bz^2 V1^2 + 2 Ex^2 V1^2 - 2 Ey^2 V1^2 -
2 Ez^2 V1^2 - 2 V0^2 V1^2 + V1^4 - 8 Bz Ex V0 V2 + 8 Bx Ez V0 V2 +
8 Bx By V1 V2 + 8 Ex Ey V1 V2 - 2 Bx^2 V2^2 + 2 By^2 V2^2 -
2 Bz^2 V2^2 - 2 Ex^2 V2^2 + 2 Ey^2 V2^2 - 2 Ez^2 V2^2 -
2 V0^2 V2^2 + 2 V1^2 V2^2 + V2^4 + 8 By Ex V0 V3 - 8 Bx Ey V0 V3 +
8 Bx Bz V1 V3 + 8 Ex Ez V1 V3 + 8 By Bz V2 V3 + 8 Ey Ez V2 V3 -
2 Bx^2 V3^2 - 2 By^2 V3^2 + 2 Bz^2 V3^2 - 2 Ex^2 V3^2 -
2 Ey^2 V3^2 + 2 Ez^2 V3^2 - 2 V0^2 V3^2 + 2 V1^2 V3^2 +
2 V2^2 V3^2 + V3^4 + 2 Bx^2 X0^2 + 2 By^2 X0^2 + 2 Bz^2 X0^2 +
2 Ex^2 X0^2 + 2 Ey^2 X0^2 + 2 Ez^2 X0^2 - 2 V0^2 X0^2 -
2 V1^2 X0^2 - 2 V2^2 X0^2 - 2 V3^2 X0^2 + X0^4 - 8 Bz Ey X0 X1 +
8 By Ez X0 X1 + 8 V0 V1 X0 X1 - 2 Bx^2 X1^2 + 2 By^2 X1^2 +
2 Bz^2 X1^2 - 2 Ex^2 X1^2 + 2 Ey^2 X1^2 + 2 Ez^2 X1^2 -
2 V0^2 X1^2 - 2 V1^2 X1^2 + 2 V2^2 X1^2 + 2 V3^2 X1^2 -
2 X0^2 X1^2 + X1^4 + 8 Bz Ex X0 X2 - 8 Bx Ez X0 X2 +
8 V0 V2 X0 X2 - 8 Bx By X1 X2 - 8 Ex Ey X1 X2 - 8 V1 V2 X1 X2 +
2 Bx^2 X2^2 - 2 By^2 X2^2 + 2 Bz^2 X2^2 + 2 Ex^2 X2^2 -
2 Ey^2 X2^2 + 2 Ez^2 X2^2 - 2 V0^2 X2^2 + 2 V1^2 X2^2 -
2 V2^2 X2^2 + 2 V3^2 X2^2 - 2 X0^2 X2^2 + 2 X1^2 X2^2 + X2^4 -
8 By Ex X0 X3 + 8 Bx Ey X0 X3 + 8 V0 V3 X0 X3 - 8 Bx Bz X1 X3 -
8 Ex Ez X1 X3 - 8 V1 V3 X1 X3 - 8 By Bz X2 X3 - 8 Ey Ez X2 X3 -
8 V2 V3 X2 X3 + 2 Bx^2 X3^2 + 2 By^2 X3^2 - 2 Bz^2 X3^2 +
2 Ex^2 X3^2 + 2 Ey^2 X3^2 - 2 Ez^2 X3^2 - 2 V0^2 X3^2 +
2 V1^2 X3^2 + 2 V2^2 X3^2 - 2 V3^2 X3^2 - 2 X0^2 X3^2 +
2 X1^2 X3^2 + 2 X2^2 X3^2 +
X3^4 + (-8 I Bx V1 X0 - 8 I By V2 X0 - 8 I Bz V3 X0 +
8 I Bx V0 X1 - 8 I Ez V2 X1 + 8 I Ey V3 X1 + 8 I By V0 X2 +
8 I Ez V1 X2 - 8 I Ex V3 X2 + 8 I Bz V0 X3 - 8 I Ey V1 X3 +
8 I Ex V2 X3) #1 + (2 Bx^2 + 2 By^2 + 2 Bz^2 - 2 Ex^2 -
2 Ey^2 - 2 Ez^2 + 2 V0^2 - 2 V1^2 - 2 V2^2 - 2 V3^2 - 2 X0^2 +
2 X1^2 + 2 X2^2 + 2 X3^2) #1^2 + #1^4 &, 1)
```