a>2,x属于R,M=a+{1/(a-2)},N=(1/2)^(x^2-2),则MN大小关系
问题描述:
a>2,x属于R,M=a+{1/(a-2)},N=(1/2)^(x^2-2),则MN大小关系
答
a>2,a-2>0
M=a+{1/(a-2)}=(a-2)+1/(a-2)+2≥2+2=4
N=(1/2)^(x^2-2)≤(1/2)^(-2)=4
M≥N