Quadratic equations with complex roots

1003102504

Level: 
B
Find the set of all complex roots of the following quadratic equation. x2+4x+8=0
{22(cos⁡3π4+i⋅sin⁡3π4);22(cos⁡5π4+i⋅sin⁡5π4)}
{2(cos⁡3π4+i⋅sin⁡3π4);2(cos⁡5π4+i⋅sin⁡5π4)}
{22(cos⁡π4+i⋅sin⁡π4);22(cos⁡7π4+i⋅sin⁡7π4)}
{2(cos⁡π4+i⋅sin⁡π4);2(cos⁡7π4+i⋅sin⁡7π4)}