解答：由根的判别式Δ=m²－4﹙m＋1﹚=0∴解得：m=2±2√2
x^2+m/(m+1) x+1/(m+1)=[x+m/2(m+1)]^2+1/(m+1)-[m/2(m+1)]^2所以1/(m+1)-[m/2(m+1)]^2=0m=1+根号3或-根号3
5
