Sin π/4 + cos(-3π/4) - 2·sin(-π/6) + 2·cos 5π/6 = √2/2 + (-√2/2) - 2·(-1/2) + 2·1/2 = √2/2 - √2/2) + 1 + 1 = 2
3·cos π/3 - 2·sin 2π/3 + 7·cos(-2π/3) - sin(-5π/4) = 3·1/2 - 2·√3/2 + 7·(-1/2) - √2/2 = 3/2 - √3 - 7/2 - √2/2 = -2 - √3 - √2/2
3·cos 7π/4 + 2·sin 3π/4 - sin(-9π/4) + 7·cos 13π/2 = 3·√2/2 + 2·√2/2 - (-√2/2) + 7·0 = 4·√2/2 = 2√2
2·sin(-5π/6) + 11·cos(-7π/3) + sin 7π/6 - 8·cos 2π/3 = 2·(-1/2) + 11·1/2 + (-1/2) - 8·(-1/2) = -1 + 11/2 - 1/2 + 4 = 8