IDNLearn.com makes it easy to find accurate answers to your specific questions. Our platform offers detailed and accurate responses from experts, helping you navigate any topic with confidence.

Find all complex solutions of the equation x^4 + x^2 - 6 = 0

Sagot :

[tex]x^4+x^2-6=0 \\ (x^2)^2+x^2-6=0 \\ \\ a=1 \\ b=1 \\ c=-6 \\ b^2-4ac=1^2-4 \times 1 \times (-6)=1+24=25 \\ \\ x^2=\frac{-b \pm \sqrt{b^2-4ac}}{2a}=\frac{-1 \pm \sqrt{25}}{2 \times 1}=\frac{-1 \pm 5}{2} \\ x^2=\frac{-1-5}{2} \ \lor \ x^2=\frac{-1+5}{2} \\ x^2=\frac{-6}{2} \ \lor \ x^2=\frac{4}{2} \\ x^2=-3 \ \lor \ x^2=2 \\ x=\pm \sqrt{-3} \ \lor \ x=\pm \sqrt{2} \\ \boxed{x=-i\sqrt{3} \hbox{ or } x=i\sqrt{3} \hbox{ or } x=-\sqrt{2} \hbox{ or } x=\sqrt{2}}[/tex]
[tex]x^4+x^2-6=0\\ x^4+3x^2-2x^2-6=0\\ x^2(x^2+3)-2(x^2+3)=0\\ (x^2-2)(x^2+3)=0\\ x^2-2=0 \vee x^2+3=0\\ x^2=2 \vee x^2=-3\\ x=-\sqrt2 \vee x=\sqrt2 \vee x=-i\sqrt3 \vee x=i\sqrt3[/tex]