MATLAB Help using fzero function in matlab

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The discussion revolves around solving the nonlinear differential equation dy/dt = 3sin(y) + y - 2 and finding its equilibrium points using the fzero function in MATLAB. The user successfully generated a direction field to visualize the system's behavior and identified that the equilibrium points are approximately around 0.5 and 4. There is a suggestion that equilibrium points can be found by setting the right-hand side of the equation to zero and treating it as an algebraic equation. While one participant mentions using Mathematica, they encourage the user to utilize MATLAB's help function for guidance on using fzero. The conversation emphasizes the importance of understanding the relationship between the differential equation and its equilibrium points for effective problem-solving.
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Hey guys i have nonlinear equation: dy/dt = 3siny + y - 2. I got the direction field with this

>> [T,Y] = meshgrid(-5:00.2:5, -5:0.2:5);
>> S = (3*sin(Y))+Y-2;
>> L = sqrt(1 + S.^2);
>> quiver(T, Y, 1./L, S./L, 0.5), axis tight
>> xlabel 't', ylabel 'y'
>> title 'Direction Field for dy/dt = (3*sin(Y))+Y-2'

NOw i need to use fzero function to find approximate values for all the equilibria of teh system. I just dont' know how to use fzero with a dif equation like this. ANy help is appreciated. thanks Also, i know the values are around 0.5 and 4.
 
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Pepsi24chevy said:
Hey guys i have nonlinear equation: dy/dt = 3siny + y - 2. I got the direction field with this

>> [T,Y] = meshgrid(-5:00.2:5, -5:0.2:5);
>> S = (3*sin(Y))+Y-2;
>> L = sqrt(1 + S.^2);
>> quiver(T, Y, 1./L, S./L, 0.5), axis tight
>> xlabel 't', ylabel 'y'
>> title 'Direction Field for dy/dt = (3*sin(Y))+Y-2'

NOw i need to use fzero function to find approximate values for all the equilibria of teh system. I just dont' know how to use fzero with a dif equation like this. ANy help is appreciated. thanks Also, i know the values are around 0.5 and 4.

The equilibrium points for an autonomous DE are the values of y such that the RHS=0. If I plot the RHS as a function of y, I get 3 zeros. I use Mathematica so can't help with matlab. Doesn't it have a help function? You know, place the cursor on the function then press the F1 key. Surely you can just treat it (RHS) as an algebraic equation in y and solve for the roots right?
 

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