设2^(3-2X)≤0.5^(3X-4)则X的取值范围是?
问题描述:
设2^(3-2X)≤0.5^(3X-4)则X的取值范围是?
已知X+X^(-1)=3,则X^2+X^(-2)的值为?
答
1.2^(3-2X)≤0.5^(3X-4)
2^(3-2X)≤(1/2)^(3X-4)
2^(3-2X)≤2^-(3X-4)
3-2x≤-3x+4
x≤1
2.X^2+X^(-2)
=X^2+2+X^(-2)-2
=[X+X^(-1)]^2-2
=3-2
=1