Cos(2x+π/3)=1/2
2x+π/3=<u>+</u> π/3 + 2πk, k∈Z
1) 2x+π/3 =π/3 +2πk, k∈Z
2x=π/3 - π/3 +2πk
2x=2πk
x=πk, k∈Z
2) 2x+π/3=-π/3 +2πk, k∈Z
2x= -π/3 - π/3 +2πk
2x= -2π/3 +2πk
x= -π/3 + πk, k∈Z
Ответ: πk, k∈Z;
-π/3 +πk, k∈Z.
<span>7/12+1/4=7/12+3/12=10/12=5/6
8/16÷5=8/16*1/5=8/80=1/10</span>
4 × -1 × (2× -1 + у) - 2 × -1 (2 × у - 5 × -1) = -4(-2+у) + 2(2у+5)= 8-4у+4у+10=18