tgX * ctgX = 1
(sinX)^2 + (cosX)^2 = 1
(ctgX)^2 = (1 + cos(2X)) / (1 - cos(2X))
cos(-5pi/3) = cos(5pi/3) = 1/2
1) 1 + (1 + cos(-5P/3)) / (1 - cos(-5P/3)) = 1 + 1 = 2
2) -( (sin(P/6))^2 + (cos(P/6))^2 ) = - 1
Объяснение:
tgX * ctgX = 1
(sinX)^2 + (cosX)^2 = 1
(ctgX)^2 = (1 + cos(2X)) / (1 - cos(2X))
cos(-5pi/3) = cos(5pi/3) = 1/2
1) 1 + (1 + cos(-5P/3)) / (1 - cos(-5P/3)) = 1 + 1 = 2
2) -( (sin(P/6))^2 + (cos(P/6))^2 ) = - 1
Объяснение: