Lg56 = lg7*2^3 = lg7 + lg2^3 = log2(7)/log2(10) + 3lg2 = log2(7)*lg2 + 3lg2 = ab+3b = b(a+3)
N
n+1
n+2
n^2+(n+1)^2+(n+2)^2=1454
n^2+n^2+2n+1+n^2+4n+4=1454
3n^2+6n+5=1454
3n^2+6n-1449=0
n^2+2n-483=0
D=4+1932=1936
√D=44
n1= (-2+44)/2=21
n2=(-2-44)/2=-23 - не подходит, т.к. n >0 - натуральное число
Ответ: 21, 22, 23
<em>Косинус -четная функция, сos(x-9π/2)=сos(x-4π-π/2)=сos(4π+π/2-x)=</em>
<em>сos(π/2-x)=sinx</em>
<em>2sinx+cosx=sinx</em>
<em>sinx+cosx=0</em>
<em>tgx=-1; </em><em>x=-π/4+πn n∈Z</em>
X - стоимость
P - коэффициент подоражания
![X(1+p)(1-p) = X*0,96](https://tex.z-dn.net/?f=X%281%2Bp%29%281-p%29%20%3D%20X%2A0%2C96)
![1-p^2=0,96](https://tex.z-dn.net/?f=1-p%5E2%3D0%2C96)
![p^2=0,04](https://tex.z-dn.net/?f=p%5E2%3D0%2C04)
![p=0,2](https://tex.z-dn.net/?f=p%3D0%2C2)
Изначально подорожали на 20%