已知a>0,b>0,且(1÷a)+(1÷b)-[1÷(a-b)]=0,求a÷b的值

2025-06-22 09:22:13
推荐回答(2个)
回答1:

√因为1/a+1/b-1/(a-b)=0,所以a²-b²=ab,则a/b-b/a=1
设a/b=x,则x-1/x=1
即x²-x-1=0,解得x=(1±√3)/2

回答2:

1/a+1/b-1/(a-b)=0
(a+b)/ab=1/(a-b)
(a+b)(a-b)=ab
a²-b²=ab
a²/a²-(b/a)²=b/a
1-(b/a)²=b/a
(b/a)²+(b/a)-1=0
b/a=(-1±√5)/2
∵a>0,b>0, a/b>0
∴b/a=(-1+√5)/2