Question

Find all the roots of y = x³ + 3x² + 6x + 4.

Answer 1

x = -1

Explanation:

If x = -1

(-1)³ + 3(-1)² + 6(-1) + 4

-1 + 3 -6 + 4

-7 + 7

0

1. 3. 6. 4

+. +. +

-1. -1 -2. -4

1 2. 4 0

(x+1)(x² + 2x + 4) = 0

(x+1) = 0

x = -1

x² + 2x + 4 = 0

discriminant = 4 -4(4) = 4 - 16 = -12

impossible