MATLAB/Exp6_2.m at main · Subhashkolanu/MATLAB · GitHub

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clc
clear all
close all
syms x y
f = x^4 - y^4 - 2*x^2 + 2*y^2;
fx = diff(f, x);
fy = diff(f, y);
[xc, yc] = solve([fx==0,fy==0],[x,y]);
K = [xc, yc];
disp('Stationary Points are:')
disp(K);
r = diff(fx,x);
t = diff(fy,y);
s = diff(fx,y);
for i = 1:length(xc)
    xc1 = xc(i);
    yc1 = yc(i);
    r1 = subs(r,[x,y],[xc1,yc1]);
    s1 = subs(s,[x,y],[xc1,yc1]);
    t1 = subs(t,[x,y],[xc1,yc1]);
    D = r1*t1 - s1^2;
    if D > 0
        if r1 > 0
            M = 'MINIMA';
          fmin = subs(f,[x,y],[xc1,yc1])

        else
            M = 'MAXIMA';
                fmax = subs(f,[x,y],[xc1,yc1])

        end
        elseif D < 0
            M = 'SADDLE POINT';

        else
            M = 'INCONCLUSIVE';
          end
fprintf('point(%s,%s):%s\n',char(xc1),char(yc1),M);

    end