Question

Решение триганометрического неравенства.( подробно)
(sinx+cosx)^2≥ 1/2

Answer 1

sin²+2sinxcosx+cos²x≥1/2
1+sin2x≥1/2
sin2x≥-1/2
-π/6+2πn≤2x≤7π/6+2πn
x∈[-π/12+πn;7π/12+πn]