a=根号3-根号2>0b=2-根号3>0c=根号5-2>01/a=(根号3+根号2)/(3-2)=根号3+根号21/b=(2+根号3)/(4-3)=2+根号31/c=(根号5+2)/(5-4)=根号5+2∵2>根号2∴2+根号3>根号3+根号2∴1/b>1/a∵根号5>根号3∴根号5+2>2+根号3∴1/c>1/b∴1/c>1/b>1/a又a,b,c>0∴a>b>c