√(a^2-4√2) = √m-√nm＞n＞0a^2-4√2 = m^2+n^2-2mnm^2+n^2 = a^2,-4√2=-2mnmn = 2√2m＞n＞0∴m=2,n=√2；或m=2√2,n=1当m=2,n=√2时,m^2+n^2=6不是完全平方数当m=2√2,n=1时,m^2+n^2=9是完全平方数∴a = 3,m=2...