Tagged Questions
0
votes
0answers
87 views
Solve[polynomial, x, Reals] doesn't get all real roots or correct ones?
My main confusion is about the difference between the two code blocks at the end of this long spiel, but the spiel contains the code to create the polynomial if its coefficients are helpful for ...
0
votes
2answers
79 views
Approximate solution to system of polynomial equations
I'd like to solve approximately the following system of equations for $a_1$, $a_2$, $\alpha_1$ and $\alpha_2$ all real and nonzero:
...
5
votes
2answers
118 views
How to find monotonically increasing intervals of a function
I tried this code, but not working
Clear[f];
f[x_] := x^3 - 3 x + 2;
ForAll[{x1, x2}, x1 < x2, f[x1] < f[x2]]
Reduce[%, {x1, x2}, Reals]
I expected the ...
0
votes
0answers
108 views
symbolic solution for a system of nonlinear equations in mathematica
Would appreciate any help on the following in mathematica I cant figure it out. I have a system of equations that I am trying to solve symbolically. I have 9 equations and 8 unknowns (I have also ...
0
votes
1answer
62 views
Solving one equation, then inputting the values into another for NonlinearModelFit
Considering the equation
a*x^3 + a*x^2 + x + b == 0
I'm looking to find the best value for a and ...
2
votes
1answer
103 views
How to transform an expression using algebraical instead of pattern rules [duplicate]
I would like to transform rules algebraically. A very simple example would be: -
k^2 - 2 k x + x^2 /. {2*k -> 1}
This transforms to: -
$$k^2-2 k x+x^2$$
...
0
votes
2answers
617 views
Solving cubic equation for real roots
I'm looking to solve the following cubic equation for x:
$\beta\, x^3 - \gamma \,x = c$. I have plugged in some sample values ($\beta = 2$, $\gamma = 5$ and $c = 2$). When I try to solve this ...
0
votes
0answers
26 views
Handling “Solve was unable to solve the system with inexact coefficient” errors [duplicate]
Possible Duplicate:
How to get rid of warnings when using Solve on an equation with inexact coefficients?
I've been trying to calculate the following in Mathematica:
...
5
votes
4answers
807 views
How to get exact roots of this polynomial?
The equation $$ 64x^7 -112x^5 -8x^4 +56x^3 +8x^2 -7x - 1 = 0 $$
has seven solutions $x = 1$, $x = -\dfrac{1}{2}$ and $x = \cos \dfrac{2n\pi}{11}$, where $n$ runs from $1$ to $5$. With ...
5
votes
3answers
664 views
First positive root
Simple question but problem with NSolve.
I need help how to extract first positive root?
For example:
...
2
votes
2answers
245 views
1
vote
2answers
242 views
8
votes
3answers
637 views
Checking if the roots of a function are real
I'm trying to determine if the roots of a function are real. How would you do that?
(In particular I'm interested in verifying that the roots of LegendreP[6, x] ...
2
votes
2answers
185 views
How to find solutions that yield of root of unity?
I have a polynomial with coefficients that are integer polynomials in another (complex) variable. For example:
1 + (1 - v^2) #1 + (-3 - v^2) #1^2 + #1^3 &
I ...
10
votes
1answer
436 views
Find roots of polynomial in field extension $GF(2^n)$?
How can I find roots of polynomial in extension field $GF(2^n)$?
