(a+√3*b)^2=3+a^2-4√3,a^2+√3*2ab+3b^2=3+a^2-4√3√3*(2ab+4)=3-3b^2,由于a、b为有理数,所以,2ab+4=0,且 3-3b^2=0,因此 a=-2,b=1或a=2,b=-1.当a=-2,b=1时,√a+b无意义；当a=2,b=-1时,√a+b=-1+√2....