Question

{х+y=П/2
{cosx+cosy=0 помогите?

Answer 1

{x+y=π/2
{cosx+cosy=0

{y=π/2-x
{cosx+cos(π/2-x)=0
 cosx+sinx=0 |:cosx≠0
 1+tgx=0
  tgx=-1
  x=3π/4+πn, n∈Z ( или = -π/4+πn, n∈Z (это одно и то же)
  y=π/2-(3π/4+πn)
  y=2π/4-3π/4-πn
  y=-π/4-πn, n∈Z
Ответ: (-π/4+πn; -π/4-πn), n∈Z