write a vector with 3 values inside a loop

Hi everyone,

I have a code and I'm looking to find z in which real values of y-1=0. Here eigA find eigenvalues of $3x3$ matrix hence y(:,k) has 3 values for each k. My question is how can I find the zeros z and I have 3 values for each k?

X = 2*pi; %not the whole code
N = 10;
n = 3;
z = linspace(0.475,0.495,100);
y = z; 
for k = 1:length(z) 
    y(:,k) = eigA(z(k),X,N,n)
end