函数y=[log1/4(x)]^2-log1/4(x)^2+5,x∈[2,4]的值域是_____
问题描述：
函数y=[log1/4(x)]^2-log1/4(x)^2+5,x∈[2,4]的值域是_____
其中1/4为底数,x为真数
网上有答案,但是看不懂,希望数学高手帮忙解答,如果答的好,有5~10加分哟~~
答
y=[log(1/4)x]^2-log(1/4)x^2+5
=[log(1/4)x]^2-2log(1/4)x+5
=[log(1/4)x-1]^2+4
∵x∈[2,4],log(1/4)x-1好像答案不对吧是错了，抱歉y=[log(1/4)x]^2-log(1/4)x^2+5 =[log(1/4)x]^2-2log(1/4)x+5 =[log(1/4)x-1]^2+4∵x∈[2,4],log(1/4)x