Using that 3 is the real root of the cubic equation x^3-27=0, show that the complex roots of the cubic satisfy the quadratic equation x^2+3x+9=0.

hence or otherwise find the three cube roots of 27 giving your answers in the form a+ib

thankyou!

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- Nov 12th 2012, 09:40 AMineedmathshelpComplex numbers (roots of equations) help
Using that 3 is the real root of the cubic equation x^3-27=0, show that the complex roots of the cubic satisfy the quadratic equation x^2+3x+9=0.

hence or otherwise find the three cube roots of 27 giving your answers in the form a+ib

thankyou! - Nov 12th 2012, 09:50 AMPlatoRe: Complex numbers (roots of equations) help