Question

已知2^a=3,2^b=6,2^c=12,则a,b,c的关系是(    )

A.成等差数列但不成等比数列                 B.成等差数列又成等比数列

C.成等比数列但不成等差数列                 D.不成等差数列也不成等比数列

Answer 1

A

解析：a=log₂3,b=log₂6,c=log₂12,

∴2b=a+c.∴成等差数列.

由a·c=log₂3·log₂12≠(log₂6)²,

∴不成等比数列.