解方程:9x^4-4x^2+4x-1=0

解方程:9x^4-4x^2+4x-1=0

9x^4=4x^2-4x+1=(2x-1)^2
3x^2=2x-1
3x^2-2x+1=0
(3x+1)(x-1)=0
x=1或-1/3