Cos(8x-π/8)≥√3*21/42
cos(8x-π/8)≥√3/2
2πn-π/6≤8х-π/8≤2πn+π/6, n∈Z
2πn-π/6+π/8≤8х≤2πn+π/6+π/8
2πn-π/24≤8х≤2πn+7π/24
πn/4-π/192<span>≤х≤πn/4+7π/192
</span>x∈[πn/4-π/192; <span>πn/4+7π/192</span>]
Y=log7(4-x^2)
4-x^2>0
2^2-x^2>0
(2-x)(2+x)>0
2-x>0 2+x>0
-x>-2 x>-2
x<2
Графики параллельны, если К1=К2 и м1 не равно м2.