[2 cos ( - π/3)]² - 4 [ctg (-π/6)]

Question

[2 cos ( - π/3)]² - 4 [ctg (-π/6)]

Answer 1

(2cos(-π/3))² - 4ctg(-π/6) = (2 · 1/2)² + 4ctgπ/6 = 1 + 4 · √3 = 4√3 + 1