Question 490686


 if you have the roots {{{x1 = -1+4i}}} and {{{x2 = -1-4i}}} you can recover the quadratic equation by forming 


{{{(x - (-1+4i))(x -( -1-4i))=0}}}

{{{(x +1-4i)(x +1+4i) = 0}}}

{{{x^2+x+4ix+x +1+4i-4ix-4i-(4i)^2=0}}}


{{{x^2+x+cross(4ix)+x +1+cross(4i)-cross(4ix)-cross(4i)-(16i^2)=0}}}


{{{x^2+x+x +1-(16(-1))=0}}}


{{{x^2+2x+1-(-16)=0}}}


{{{x^2+2x+1+16=0}}}


{{{x^2+2x+17=0}}}.......your answer

check it:

*[invoke quadratic_formula 1, 2, 17, "x"]