To solve the binomial equation, we'll apply the formula of
the sum of cubes:
a^3 + b^3 = (a+b)(a^2 - ab +
b^2)
a^3 = x^3
a =
x
b^3 = 2^3 = 8
b =
2
x^3 + 8 = (x+2)(x^2 - 2x +
4)
If x^3 + 8 = 0, then (x+2)(x^2 - 2x + 4) =
0
If a product is zero, then each factor could be
zero.
x + 2 = 0
We'll subtract
2 both sides:
x1 =
-2
x^2 - 2x + 4 =
0
We'll apply the quadratic
formula:
x2 = [2 +
sqrt(4-16)]/2
x2 =
(2+2isqrt3)/2
We'll factorize by
2:
x2 =
2(1+isqrt3)/2
x2 =
1+isqrt3
x3 = 1-
isqrt3
The roots of the
equation are: {-2 , 1+isqrt3, 1- isqrt3 }.
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