206,884 views
39 votes
39 votes
Solve x^4 - 3x^2 +2 = 0 using substitution.

U=

x
x^2
3x^2
x^4

Answer- x^2
(on edge)

User Sagar Trehan
by
2.4k points

2 Answers

13 votes
13 votes

Answer:

its 3^x

Explanation:

just did it

User Roy Miloh
by
3.0k points
24 votes
24 votes

Answer:

x = ± 1 , x = ±
√(2)

Explanation:

Let u = x² , then


x^(4) - 3x² + 2 = 0 , can be expressed as

u² - 3u + 2 = 0 ← in standard form

(u - 1)(u - 2) = 0 ← in factored form

Equate each factor to zero and solve for u

u - 1 = 0 ⇒ u = 1

u - 2 = 0 ⇒ u = 2

Change the variable u back to x

x² = 1 ( take square root of both sides )

x = ± 1

or

x² = 2 ( take square root of both sides )

x = ±
√(2)

User Attila Kling
by
2.7k points