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Rikke
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how to solve many polynomial equations listed in a matrix?

Asked by Rikke
on 24 Mar 2019
Latest activity Commented on by Rikke
on 25 Mar 2019
I have a matrix where each row is a polynomial equation:
A=[0.01 620.085 -3750
0.01 620.082 -3750
0.01 620.079 -3750
0.01 620.076 -3750];
I want to solve every row of matrix A. How can i do that, I tried:
for i=1:length(A)
I(i)=roots(A(i,:))';
end
I want to get the answer as follows:
I= [I(1,1) I(1,2)
I(2,1) I(2,2)
I(3,1) I(3,2)
I(4,1) I(4,2)];

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2 Answers

Answer by madhan ravi
on 24 Mar 2019
 Accepted Answer

Roots = arrayfun( @(x) roots( A( x, : ) ), 1 : 4, 'un', 0 );
[ Roots{ : } ].'

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Answer by Matt J
on 24 Mar 2019
Edited by Matt J
on 24 Mar 2019

Here's a method withoutt loops,
[a,b,c]=deal(A(:,1),A(:,2),A(:3));
D=sqrt(b.^2-4.*a.*c);
I=[-b-D, -b+D]./(2.*a);

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