cos2a+1/2tga•ctga = 2cos(а)^2 - 1 + 1 / 2tg a * 1/tg a = 2cos(а)^2 / 2 = cos(а)^2
cos(π/6)^2 = (√3/2)^2 = 3/4
Объяснение:
cos2a+1/2tga•ctga = 2cos(а)^2 - 1 + 1 / 2tg a * 1/tg a = 2cos(а)^2 / 2 = cos(а)^2
cos(π/6)^2 = (√3/2)^2 = 3/4
Объяснение: