The complex conjugate of 2-3i is also a root of z^3+pz^2+qz-13p=0. Find a quadratic factor of z^3+pz^2+qz-13p=0 with real coefficients and thus find the real root of the equation.

z-2+3i times z-2-3i = z2-4z+13. z3-2z2+5z+26 divided by z2-4z+13 = z+2. Therefore the real root is z=-2.

WN

Related Maths A Level answers

All answers ▸

A curve C has the following equation: x^3 + 3y - 4(x^3)*(y^3) a) Show that (1,1) lies on C b) Find dy/dx


What is differentiation


OCR M2 A level maths June 2015 question 8


What is the integral of 2x^5 - 1/4x^3 - 5