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20 votes
Quadratic equations w complex roots
x2 - 6x + 12 = 0

User Yibuyiqu
by
3.5k points

1 Answer

13 votes

Answer:

x = 3 ± i
√(3)

Explanation:

Given

x² - 6x + 12 = 0 ( subtract 12 from both sides )

x² - 6x = - 12

Using the method of completing the square

add ( half the coefficient of the x- term )² to both sides

x² + 2(- 3)x + 9 = - 12 + 9

(x - 3)² = - 3 ( take the square root of both sides )

x - 3 = ±
√(-3) = ± i
√(3) ( add 3 to both sides )

x = 3 ± i
√(3)

User Theodore Tang
by
3.2k points