Решение
1)
а) 6cos(- π/4) - 8sin(-π/6)- 2tgπ/4 = 6*(√2/2) + 8*(1/2) - 2*1 = 3√2 + 2
б) 4tg²(-π/6) + 4cos²(-π/6) - cos(-π) = (√3/3)² + 4*(√3/2)² + 1 =
= 4*(3/9) + 3 + 1 = 4/3 + 4 - 1 + 1 = 5(1/3)
2)
а) 4sin²(3π/2 - α) - 6cos²(π/2 - α) = 4cos²α - 6sin²α = 4*(1 - sin²α) - 6sin²α =
4 - 10sin²α
α = π/6
4 - 10sin²(π/6) = 4 - 10*(1/2)² = 3/2 = 1,5