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
По моему так
cos(x-y)=cosx*cosy+sinx*siny cos(x+y)=cosx*cosy-sinx*sinysin(x-y)=sinx*cosy-cosx*siny sin(x+y)=sinx*cosy+cosx*siny<span>.
Ответ: </span>sinx*cosy+cosx*siny
Sin45cos45+3cos60tg180=√/2/2*√2/2+3*1/2*0=2/4=1/2