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Solve these unkowns x and y using these 2 simultaneous equations

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Eq1= 2760 * sin (200) + m3R3L3 * sin (107) + m4R4L4 * sin (307) = 0
Eq2= 2760 * cos (200) + m3R3l3 * cos (107) + m4R4L4 * cos(307) = 0
I want to get m3r3l3 and m3r4l4 we can consider m3r3l3 as x and m4r4l4 as y

Accepted Answer

Walter Roberson
Walter Roberson on 29 Oct 2023
syms m3R3l3 m4R4l4
Eq1 = 2760 * sind(sym(200)) + m3R3l3 * sind(sym(107)) + m4R4l4 * sind(sym(307)) == 0
Eq1 = 
Eq2 = 2760 * cosd(sym(200)) + m3R3l3 * cosd(sym(107)) + m4R4l4 * cosd(sym(307)) == 0
Eq2 = 
sol = solve([Eq1, Eq2])
sol = struct with fields:
m3R3l3: (2760*(cos(pi/9)*sin((53*pi)/180) + cos((53*pi)/180)*sin(pi/9)))/(cos((53*pi)/180)*sin((73*pi)/180) - cos((73*pi)/180)*sin((53*pi)/180)) m4R4l4: (2760*(cos(pi/9)*sin((73*pi)/180) + cos((73*pi)/180)*sin(pi/9)))/(cos((53*pi)/180)*sin((73*pi)/180) - cos((73*pi)/180)*sin((53*pi)/180))
simplify(sol.m3R3l3)
ans = 
simplify(sol.m4R4l4)
ans = 
  2 Comments
nathalie
nathalie on 29 Oct 2023
Yes there any way to solve this final answer to get normal numbers? On matlab?
Walter Roberson
Walter Roberson on 29 Oct 2023
No, π is transcendental. It is mathematically impossible to express it in terms of a finite series of "algebraic numbers". It is not the root of any finite polynomial with rational coefficients. π is one of the most abnormal real numbers that exist.
However you can get a more compact answer than the above:
syms m3R3l3 m4R4l4
Eq1 = 2760 * sind(sym(200)) + m3R3l3 * sind(sym(107)) + m4R4l4 * sind(sym(307)) == 0
Eq1 = 
Eq2 = 2760 * cosd(sym(200)) + m3R3l3 * cosd(sym(107)) + m4R4l4 * cosd(sym(307)) == 0
Eq2 = 
sol = solve([Eq1, Eq2])
sol = struct with fields:
m3R3l3: (2760*(cos(pi/9)*sin((53*pi)/180) + cos((53*pi)/180)*sin(pi/9)))/(cos((53*pi)/180)*sin((73*pi)/180) - cos((73*pi)/180)*sin((53*pi)/180)) m4R4l4: (2760*(cos(pi/9)*sin((73*pi)/180) + cos((73*pi)/180)*sin(pi/9)))/(cos((53*pi)/180)*sin((73*pi)/180) - cos((73*pi)/180)*sin((53*pi)/180))
simplify(sol.m3R3l3, 'steps', 1000)
ans = 
simplify(sol.m4R4l4, 'steps', 1000)
ans = 

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More Answers (1)

Torsten
Torsten on 29 Oct 2023
Moved: Torsten on 29 Oct 2023
I think you want to use sind and cosd instead of sin and cos.
This is a linear system of equations in m3R3L3 and m4R4L4. You know how to solve linear systems of equations ?

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