Question 1410b

Complex Numbers
2010 Paper 2 Question 1 Variant

Question

(a)
Solve the equation x2+4x+5=0.{x^2 + 4 x + 5=0.}
[2]
(b)
One root of the equation
x44x312x2+ax+b=0,x^4 - 4 x^3 - 12 x^2 + ax + b=0,
where a{a} and b{b} are real, is x=4i.{x=4 - \mathrm{i}.}
Find the values of a{a} and b{b} and the other roots.
[5]

Answer