# What are the Solutions of the Equation x^{4} + 3x^{2} + 2 = 0? Use "u" substitution to solve.

We will be using the "u" substitution to solve this.

## Answer: The Solutions of the Equation are x^{4} + 3x^{2} + 2 = 0 are x = i, -i, i√2, -i√2

Let us sole this step by step

**Explanation:**

Given, x^{4} + 3x^{2} + 2 = 0

Let u = x^{2}

⇒ u^{2} + 3u + 2 = 0

(u + 1) (u + 2) = 0

u = -1 and u = -2

⇒ x^{2} = -1 and x^{2} = -2

x_{1} = √-1 = i

x_{2} = -√-1 = -i

x_{3} = √-2 = i√2

x_{4} = -√-2 = -i√2