Mjc 2010 H2: Math Prelim

(c) Find the exact area of the triangle formed by these three roots.

So roots: [ z_0 = \sqrt[3]16 , e^i\pi/4, \quad z_1 = \sqrt[3]16 , e^i11\pi/12, \quad z_2 = \sqrt[3]16 , e^-i5\pi/12. ] Argand diagram: points on circle radius (\sqrt[3]16 \approx 2.52), arguments (\pi/4) (45°), (165°), (-75°). (c) Area of triangle = (\frac3\sqrt34 R^2) where (R = \sqrt[3]16). Mjc 2010 H2 Math Prelim

So area = (\frac3\sqrt34 (16^2/3)). (16^2/3 = (2^4)^2/3 = 2^8/3 = 4 \cdot 2^2/3 = 4\sqrt[3]4). (c) Find the exact area of the triangle

(b) On a single Argand diagram, sketch the three roots. \quad z_1 = \sqrt[3]16