2cos²(45+4a) + sin8a = 1
cos²x = (1+cos2x)/2 - формула
2cos²(45+4a) +sin8a = 1
2(1+cos2(45+4a))/2 +sin8a = 1
1+cos2(45+4a) + sin8a = 1
1+ cos(90+8a)+ sin8a = 1
cos(90+a) = -sina формула
1+ cos(90+8a) + sin8a = 1
1-sin8a +sin8a = 1
1 = 1
2cos²(45+4a) + sin8a = 1
cos²x = (1+cos2x)/2 - формула
2cos²(45+4a) +sin8a = 1
2(1+cos2(45+4a))/2 +sin8a = 1
1+cos2(45+4a) + sin8a = 1
1+ cos(90+8a)+ sin8a = 1
cos(90+a) = -sina формула
1+ cos(90+8a) + sin8a = 1
1-sin8a +sin8a = 1
1 = 1