Решение
<span>Sin7x+sin6x+sin5x = (sin7x + sin5x) + sin6x =
</span>= 2*[sin(7x + 5x)/2 * cos(7x - 5x)/2] + sin6x =
= 2*sin6x * cosx + sin6x = sin6x*(2cosx + 1)
(-2.5)^2+1.5^2=6.25+2.25=8.5
√48а²в^6=√16*3√a²√b^6=4√3|a| *|b³|=4√3*a*(-b³)=-4ab³√3
1 комбайн = (14/6)=2ч 20 мин
14 ч - 2.20= 9ч 20 мин
Ax²-4x+(3a+1)>0
D=16-4a(3a+1)<0
12a²+4a-16>0
3a²+a-4>0
D=1+48=49
a1=(-1-7)/6=-4/3
a2=(-1+7)/6=1
+ _ +
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-4/3 1
a∈(-∞;-4/3) U (1;∞)