!!!!!!!!!!!!!!!!!!!!........
Ответ:
...........................
1. (1 - 2sin² L)+ cos² L = cos 2L + 1/2 + 1/2 cos 2L = 0,5·(3cos 2L + 1)
2. (sin L - cos L)² = sin² L - 2sin L· cos L+ cos² L = 1 - 2sin L· cos L = 1 - sin 2L
3. (1 - cos2L)·ctg L = 2sin² L·cos L/sin L = 2sin L·cos L = sin 2L
<u>c²-d² </u> <u> </u><u>(с-d)(c+d) </u> <u>c+d
</u>bc-bd = b(c-d) = b<span>
</span><u>3x²-27 </u> <u>3(x-3)(x+3</u>) 3(<u>x-3)(x+3) </u> <u> 3(x+3)
</u><span>3x-x² = x(3-x) = - x(x-3) = x</span><span>
</span>