(lgx)2+lgx^3+2=0解方程(logx)^2+lgx^3+2=0

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(lgx)2+lgx^3+2=0解方程(logx)^2+lgx^3+2=0
(lgx)2+lgx^3+2=0解方程
(logx)^2+lgx^3+2=0

(lgx)2+lgx^3+2=0解方程(logx)^2+lgx^3+2=0
(lgx)^2+lgx^3+2=0
(lgx)2+3lgx+2=0
(lgx+2)(lgx+1)=0
lgx=-2或lgx=-1
x=1/100或x=1/10

(lgx)2+lgx^3+2=0
(lgx)2+3lgx+2=0
令lgx=t,则
t²+3t+2=0
(t+1)(t+2)=0
所以t=-1或t=-2
即lgx=-1,所以x=0.1,
或lgx=-2,x=0.01

(lgx)^2+lgx^3+2=0
(lgx)^2+3lgx+2=0
(lgx+1)(lgx+2)=0
lgx = -1,或lgx = -2
x = 10^(-1) = 0.1,或x = 10^(-2) = 0.01