a) Find all complex-valued solutions to the equation z^3 - 2z^2 + 4z by hand. Write each one in the form a+bi.
Mr F says: z(z^2 - 2z + 4). Factorise the quadratic by first completing the square.
b) Starting with the real-valued root, sketch all the complex-valued cuve roots of -27 in the complex plane. Against each, write its value in the form re^i(feta)
Mr F says: The real root cube root of -27 is -3. All the cube roots lie on a circle of radius 3 and are equally spaced by angle 2 pi/3 ....
If there is anything unclear in the question, let me know, thanks.