Question

已知A B C是等差数列,A C B成等比数列,求ABC比值

Answer 1

abc成等差,

所以2b=a+c acb成等比,

所以c^2=ab (2b-a)^2=ab a^2-5ab+4b^2=0

(a-4b)(a-b)=0

a=4b或a=b c=-2b或c=b

因此a:b:c=4:1:-2或a:b:c=1:1:1