emilymariec5201 emilymariec5201 22-05-2023 Mathematics contestada (ii) Prove the identity (2 – 2 cos 0) (sin + sin 20 + sin 30) = -(cos 40 - 1) sin + sin 40 (cos - 1). (iii)Find the roots of f(x) = x3 – 15x – 4 using the trigonometric formula. =