神马品牌网魔兽额外按键宏:一道高一数学简单的题目,谢谢大家！
来源：百度文库 编辑：神马品牌网 时间：2024/05/03 03:11:12
(log[3]x)^2+log[9]3x=2
(log[3]x)^2+log[9]3x=2
(lgx/lg3)^2+(lg3x/lg9)=2
(lgx/lg3)^2+(lg3x/2lg3)=2
(lgx/lg3)^2+(lgx/2lg3)+(lg3/2lg3)=2
(lgx/lg3)^2+(lgx/lg3)/2+1/2-2=0
2(lgx/lg3)^2+(lgx/lg3)-3=0
(2lgx/lg3+3)(lgx/lg3-1)=0
(1)lgx/lg3=-3/2
2lgx=-3lg3
x^2=3^(-3)
x=√3/9
(2)lgx/lg3=1
lgx=lg3
x=3