Объяснение:
1) (sin² α - cos² α + 1) / sin² α = 2
(sin² α / sin² α) - (cos² α / sin² α) + (1 / sin² α) = 2
1 - ctg² α + (1 / sin² α) = 2
1 - ctg² α + 1 + ctg² α = 2
2 = 2
2) ((1 - sin² α) / (1 - cos² α)) - ctg² α = 0
(cos² α / sin² α) - ctɡ² α= 0
ctɡ² α - ctɡ² α= 0
0 = 0
