(m^1/2-n^1/2)/(m^1/2+n^1/2)+(m^1/2+n^1/2)/(m^1/2-n^1/2)
= (m^1/2-n^1/2)*(m^1/2-n^1/2)/[(m^1/2+n^1/2) (m^1/2-n^1/2)]+ (m^1/2+n^1/2)*(m^1/2+n^1/2)/[(m^1/2+n^1/2) (m^1/2-n^1/2)]
= (m^1/2-n^1/2)^2/[(m^1/2)^2-(n^1/2)^2]+(m^1/2+n^1/2)^2/[(m^1/2)^2-(n^1/2)^2]
=(m+n-2*m^1/2*n^1/2)/(m-n)+(m+n+2*m^1/2*n^1/2)/(m-n)
=(m+n-2*m^1/2*n^1/2m+n+2*m^1/2*n^1/2)/(m-n)
=2(m+n)/(m-n)