Find x values for x^4 - 3x^2 + 2 (supposed to get x1,2= +/- 1 x3,4= +/- √2)

[Henryt]

Hello,

how to find x values for this equation please

x⁴ -3x² +2


The answers I'm supposed to find are : x_1,2= +/- 1 x_3,4= +/- √2

Thanks

 

[HallsofIvy]

First that NOT an equation because there is no "="! I am going to guess that you meant \(\displaystyle x^4- 3x^2+ 2= 0\) though it might be equal to some other number. If you let \(\displaystyle y= x^2\) then we have \(\displaystyle y^2- 3y+ 2= 0\), a quadratic equation. You could use the "quadratic formula" but this factors easily: \(\displaystyle y^2- 3y+ 2= (y- 2)(y- 1)= 0\). What must y be? And so what must x be?

 

[sinx]

Hello,

how to find x values for this equation please

x⁴ -3x² +2=0


The answers I'm supposed to find are : x_1,2= +/- 1 x_3,4= +/- √2

Thanks

I think halls also said this;
x⁴ -3x² +2=0
(x²-2)(x²-1)=0

now solve for x values.