3x^4-13x^2+4=0 Помогите пожалуйста

[latex]3 x^{4} -13 x^{2} +4=0 \\ y= x^{2} \\ 3y^{2} -13y+4=0 \\ D=169-4*4*3=121 \\ y_{1}= \frac{13-11}{6} = \frac{1}{3} \\ y_{2}= \frac{13+11}{6} = 4 \\ x^{2} =4 \\ x_{1}=2\\ x_{2}=-2 \\ x^{2} = \frac{1}{3} x_{3}= \frac{ \sqrt{3} }{3} \\ x_{4}= -\frac{ \sqrt{3} }{3} \\ [/latex]