A12 - 4
A13 - 2
A14 - 3
A15 - 4
(sin16B+sin4B)+(sin22B+sin10B)= 2sin (16B+4B)/2*cos(16B-4B)/2+ 2sin(22B+10B)/2*cos(22B-10B)/2= 2sin 10B*cos6B+ 2sin16Bcos6B= 2 cos6B(sin10B+sin16B)=2 cos6B( 2sin (10B+16B)/2*sin (10B-16B)/2)=4cos6B*sin13B*cos (-3B) , т.к. cos(-3B)=cos 3B в ответе минус не пишется.
Ответ: 4cos6B*sin13B*cos3B
Х^2 + V x + N = 0
1) - 13
( - 13 )^2 - 13V + N = 0
N - 13V + 169 = 0
2) 4
4^2 + 4V + N = 0
N + 4V + 16 = 0
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N = - 4V - 16
- 4V - 16 - 13V + 169 = 0
- 17V = - 153
V = 9
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N = - 4 • 9 - 16 = - 36 - 16 = - 52
9 > - 52
Ответ 9 ; - 52