How to solve this equation?

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Sara Boznik 2020-8-29

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/586103-how-to-solve-this-equation

编辑： Mario Malic 2020-9-4

采纳的回答： Ali Muhammad Hassaan

在 MATLAB Online 中打开

Hi everyone,

I want to solve this equation in Matlab. Until now I have the following code:

a=18
b=60
c=76.7
syms x
solx=solve('cos(x).*(a.*sin(x)+b)=c','x')

I get next error: Check for missing argument or incorrect argument data type in call to function 'solve'.

Error in Untitled (line 8)

solx=solve('cos(x).*(a.*sin(x)+b)=c','x')

I dont know what it is wrong, can anybody help me?

Any help is appriciated.

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Kitty Visser 2020-9-4

编辑：Kitty Visser 2020-9-4

在 MATLAB Online 中打开

i have also this error

with this function

[V1,V2,V3]=solve('(V1-V2)/R1 = Is + 2*(V3-V2)/R3','(V2 - V1)/R1 + V2/R2 + (V2-V3)/R3 = 0','(V3-V2)/R3 + V3/R4 + 2*(V3-V2)/R3=0','V1','V2','V3')

Mario Malic 2020-9-4

编辑：Mario Malic 2020-9-4

You're missing double equals sign in your equations.

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采纳的回答

Ali Muhammad Hassaan 2020-8-29

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/586103-how-to-solve-this-equation#answer_486683

在 MATLAB Online 中打开

a=18
b=60
c=76.7
syms x
eqn = cos(x).*(a.*sin(x)+b) == c
solx=solve(eqn)

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Sara Boznik 2020-8-29

Thank you!

Vladimir Sovkov 2020-8-29

The sintax is correct here but it is of no help to find the solution, because there is no real-type one, and "solve" refuses working with the complex type. To find the solution you should reformulate the problem as a system of two real-type equations for the real and imaginary parts being two unknown variables.

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