a^2+ab+b^2=a+b
(a+b)^2-ab=a+b
令a+b=t,t^2-t=ab<1/老慧4t^2
t(3/4t-1)<0
0
设a.b是不等的正数,且a^3-b^3=a^2-b^2,证明1<a+b<4/3
a^2+ab+b^2=a+b
(a+b)^2-ab=a+b
令a+b=t,t^2-t=ab<1/老慧4t^2
t(3/4t-1)<0
0
a^2+ab+b^2=a+b
(a+b)^2-ab=a+b
令a+b=t,t^2-t=ab<1/老慧4t^2
t(3/4t-1)<0
0