不等式log1/2 (4的x次方+2的x+1次方)>0
问题描述:
不等式log1/2 (4的x次方+2的x+1次方)>0
答
log1/2 (4的x次方+2的x+1次方) = log1/2 (4的x次方)× log1/2 (2的x+1次方) = log1/2 (1/2)^-2x)+ log1/2 ( 1/2)^-(x+1) =-2x×[-(x+1)] =2x(x+1)>0. 所以得x>0或x