What is the result of this ecuation, in C? x^3+x+1=0?

Question

The first answer given is wrong. Anyone having another?

Answer 1

x^3+x+1=0
y=x^3+x+1
y´= 3x^2+1 = 0 no solution
so there is only one real solution between -1 and 0
With a calculator you get
x= -0.682327804383
the complex roots are0.341163901914 +-i*1.1615414

Answer 2

x^3+x+1=0
(x+1)(x^2+x+1)=0
(x+1)= 0 --> x = -1
(x^2+x+1)=0
x = (-b+-sqrt(b^2-4ac)/2a
(-1+-sqrt(1^2-4(1)(1))/2(1)
(-1+-sqrt(1-4)/2
(-1+-isqrt(3))/2