<span>sin(pi/2+x)= - cosx
+++++++++++++</span>
2(1+cos2*2x)/2+cos10x-1=0
Cos4x+cos10x=0
<span>3;6;12
b1=3
q=6/3=2
s6=b1(q^6-1)/(q-1)=3*(2^6-1)/(2-1)=3*63=189
sn=b1(q^n-1)/(q-1)=3(2^n-1)
;.... .Найдите S(6) S(n) </span>
2х(4у-у):(2у+х)
2х*3у:(2у+х)
6ху:(2у+х)
3(а-b)(a+b)
12(m-n)(m+N)
a(x-y)(x+y)
2x(a-b)(a+b)
5(x-1)(x+1)
2(a-2)(a+2)