Question

Решите тригонометрическое неравенство
cos²x - sin²x ≥1/2

Answer 1

cos²x - sin²x ≥1/2

cos 2x ≥1/2

-π/3+2πk ≤ 2x ≤ π/3+2πk

-π/6+πk ≤ x ≤ π/6+πk, k∈Z