Roots of polynomial #3 and How to find unique values into a vector/matrice?

Forum|Forum|1 year ago
September 23, 2024
2 replies
2377 views

Hi,

How to find all roots of this equation:

Best answer by ttokoro

Depend on TOL. So need UniqueP function to select 4.

C

Cornel

Author

19-Tanzanite

Hm...I think I found a way:

We can see that only these 4 values (roots) are repeated: -0.439-1.077i, 0.584-0.431i, 0.274+0.784i, and -0.648+0.852i.

Now I am interested in how to extract/retain only those unique 4 values?

ttokoro

Answer

21-Topaz I

Depend on TOL. So need UniqueP function to select 4.

t.t.

C

Cornel

Author

19-Tanzanite

A(x) is not an array?

I do not know how to think at the differences between the two. I see that when defining x as not integer values (0.1, 0.2, 0.3, etc), then I cannot use like Cx and also I cannot use further UniqueP function. On the other hand when defining range variable as y (1,2,3, etc, integer values), then I can use UniqueP function but only when defining with matrix index as B. Maybe someone can explain a little bit this function UniqueP, and also why I cannot use A(x) with UniqueP function.

1_This-value-must-be-an-array.zip

L

LucMeekes

23-Emerald IV

Success!
Luc

W

Werner_E

25-Diamond I

Interesting!

Needless to say that the symbolic solve does not work that way in non-MC11 versions.
The symbolic would switch to float mode and returns just one solution.

Based on the graphic, it is difficult to say whether the four spikes only 'touch' the floor plan at one point (just four solutions), or whether they penetrate it and the solution consists of four circle-like shapes. In the latter case, however, there would be an infinite number of solutions, not just 43... Can you plot the solutions in the Gauß-plane?