Question

Решите неравенство: 2cos (3π/2 + 3x) ≤ -√3

Answer 1

$2cos( frac{3pi }{2} + 3x ) leq - sqrt{3} 2sin3x leq - sqrt{3} sin3x leq - frac{sqrt3}{2} 3x leq (-1)^{k+1}arcsin frac{sqrt3}{2} + pi*k, k belons to Z 3x leq (-1)^{k+1}* frac{pi}{3} + pi*k, k belongs to Z x leq (-1)^{k+1}* frac{pi}{9} + frac{pi*k}{3}, k belongs to Z$