已知根号2≤x≤8,求函数y=(log以2为底x/4的对数)×(log以2为底x/2的对数)的最值
问题描述:
已知根号2≤x≤8,求函数y=(log以2为底x/4的对数)×(log以2为底x/2的对数)的最值
答
log2X∈[1,3]
y=(log2X-2)(log2X-1),log2X∈[1,3]
=(log2X-1.5)²-0.25,log2X∈[1,3]
ymin=-0.25,ymax=2