函数f(x)在(0,+∞)上是减函数,则f(a^2-a+1)与f(3/4)大小关系是____.函数f(x)在(0,+∞)上是减函数,则f(a^2-a+1)与f(3/4)大小关系是____.A.f(a^2-a+1)≤f(3/4) B.f(a^2-a+1)≥f(3/4) C.f(a^2-a+1)<f(3/4) D.f(a^2-a+1)=f(3/4)
问题描述:
函数f(x)在(0,+∞)上是减函数,则f(a^2-a+1)与f(3/4)大小关系是____.
函数f(x)在(0,+∞)上是减函数,则f(a^2-a+1)与f(3/4)大小关系是____.A.f(a^2-a+1)≤f(3/4) B.f(a^2-a+1)≥f(3/4) C.f(a^2-a+1)<f(3/4) D.f(a^2-a+1)=f(3/4)
答
a^2-a+1=(a-1/2)^2+3/4>=3/4>0 所以答案是A.f(a^2-a+1)≤f(3/4)