Find exact solution for few angles

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Homework Help Overview

The original poster presents a set of equations involving three variables (δ, λ, and θ) that they are trying to solve for specific values. The equations are trigonometric in nature and relate to a matrix representation with given constants.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the possibility of real solutions for the equations, with some suggesting that certain equations may only yield complex solutions. There is mention of numerical methods as a potential approach to finding solutions.

Discussion Status

There is an ongoing exploration of the equations, with some participants agreeing on the likelihood of complex solutions. Suggestions for numerical approaches and transformations to potentially yield real solutions have been offered, but no consensus has been reached on a definitive method.

Contextual Notes

Participants note that the original poster's requirement for real solutions is a significant constraint, and some equations are under scrutiny for their solvability in real numbers.

abotaha
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Hi everybody,

I have a couple of equations and I need to find the values of three variables (δ, λ, and θ).
The equations are:

M[11] = -(sin(δ)*cos(λ)*sin(2*θ)+sin(2*δ)*sin(λ)*sin(θ)^2)*M[0];
M[12] = (sin(δ)*cos(λ)*cos(2θ)+(1/2)*sin(2*δ)*sin(λ)*sin(2θ))*M[0];
M[13] = -(cos(δ)*cos(λ)*cos(θ)+cos(2*δ)*sin(λ)*sin(θ))*M[0];
M[22] = (sin(δ)*cos(λ)*sin(2*θ)-sin(2*δ)*sin(λ)*cos(θ)^2)*M[0];
M[23] = -(cos(δ)*cos(λ)*sin(θ)-cos(2*δ)*sin(λ)*cos(θ))*M[0];
M[33] = sin(2*δ)*sin(λ)*M[0];

where :
M[0]= 19.817; M[11]= 32.6; M[12] = -1.3; M[13] = -7.2; M[22] = 2.2; M23 = -13.5; M[33] = -24.7;

Any help would be highly appreciated.
 
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The last one:

This is straightforward to show that there's no exist δ λ such that:

-24.7= sin(2*δ)*sin(λ)*19.817

(this can be true only if δ λ are complex)
 
I have to agree with drszdrsz; some of these equations will not have real solutions. In particular, the first and last do not have real solutions.

As for the other ones... do it numerically?
 
Thanks for the replay. I also tried to solve these equations and i found that the solution contained complex number, however, the solution suppose to be real number.
i do not know how i can processed further.
please i need some suggestions.
 
Complex numbers might reduce to real numbers if you properly transform your equations...
 

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