Question

What are the solutions of the equation x^4+3x^2+2=0? Use u substitution to solve.

Answer 1

Answer:

• Option B

Step-by-step explanation:

Solve the equation in steps below

• $x^4+3x^2+2=0$
• $x^4+x^2+2x^2+2=0$
• $x^2(x^2+1)+2(x^2+1)=0$
• $(x^2+2)(x^2+1) = 0$
• $x^2+2=0$ or $x^2+1=0$
• $x^2=-2$ or $x^2=-1$
• $x=\sqrt{-2}$ or $x=\sqrt{-1}$
• $x=\pm\ i\sqrt{2}$ or $x=\pm\ i$

Correct choice is B