how do i solve for the unknown variable

I have 3 axis x y and z. I wish to find Z such that the sum of the squares would be equal to 1.

the data is stored in a vector with 3 columns. I want to substitute the last one with an unknown such that the sum of the squares of x y and z would equal to 1.

syms zz
for i=1:90
g(i) = sqrt (gx1(i,1) * gx1(i,1) + gy1(i,1) * gy1(i,1) + zz * zz) - 1
roots(i) = solve(g(i),zz);
end

I would greatly appreciate the help. thanks Rafael

Answer 1

[Razvan]

If you have the vectors x and y

e.g.

x = 0.5 * rand(10, 1);
y = 0.5 * rand(10, 1);

Then the z is simply

z = sqrt(1 - x.^2 - y.^2);

plus or minus that, depending if you want the positive or the negative root.