My Math Fermat Guess – Taking the derivate dx~dy in the equation x^n+y^n = z^n I guess the ratio dz/dx ~= (x^(n-1)+y^(n-1)) / z^(n-1) must be able to have a prime number for z which holds true for n = 2 not 3,4,5,… for 3x,4x,5x the ratio is 7/5