how to solve the following equation?

Dear all,

I have a easy question since I am not familiar with matlab. Hope you can give me some tips? My question is as belows.

a=[1,2,3];

a=((b-2).*(b+1))./((b+3).*(b-1)):

b=?

I would like to solve b. Should I use for loop and assume a initial value of b then solve it iteratively? but I forget how to achieve this programme. Thanks for your attention.

Answer 1

[Star Strider]

Try this —

a=[1,2,3];
afcn = @(b) ((b-2).*(b+1))./((b+3).*(b-1));
[estb,fval] = fminsearch(@(b) norm(afcn(b) - a), rand)                   % Estimate For All 'a'

estb = 0.7016

fval = 1.4142

for k = 1:numel(a)
    [estba(k),fvala(k)] = fminsearch(@(b) norm(afcn(b) - a(k)), rand);      % Estimate For All 'a'
end
estba

estba = 1×3

0.3333 0.7016 0.8117

fvala

fvala = 1×3

1.0e+-4 * 0.2770 0.1710 0.5080

bv = linspace(0, 1.5);
figure
plot(bv, afcn(bv))
hold on
plot(estb, afcn(estb), 'sr', 'MarkerSize',20)
plot(estba, afcn(estba), 'pg', 'MarkerSize',15, 'MarkerFaceColor','g')
hold off
grid

Experiment to get different results

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[kimy]

Thank you so much. It works properly.

[Star Strider]

As always, my pleasure!

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