1)sin(6.5π) + cos(4.5π) = sin(π + 0.5π) + cos(π + 0.5π) = sin(0.5π) + cos(0.5π) = 1 + 0 = 1
2)ctg(21π/4) + tg(13π/4) = tan(π - π/4) + 1/tan(π + π/4) = tan(3π/4) + 1/tan(5π/4) = -1 + 1/-1 = -1 - 1 = -2
1)
sin(6.5π) + cos(4.5π) = sin(π + 0.5π) + cos(π + 0.5π) = sin(0.5π) + cos(0.5π) = 1 + 0 = 1
2)
ctg(21π/4) + tg(13π/4) = tan(π - π/4) + 1/tan(π + π/4) = tan(3π/4) + 1/tan(5π/4) = -1 + 1/-1 = -1 - 1 = -2