21●íåò ðåøåíèé { |2õ+1|=õ
21●–π/3+2πn≤x≤π/3+2πn,n*Z |y=√2cosx–1|
21●2 |2 ∫ 1 dx|
21●a6=7 (6 ÷ëåí ïðîãð)
21●π/4+πk,k*Z ( sin2x=1 )
21●π/4+kπ | tg(2π–x)=–1 |
21●–π/4+πn≤x≤π/4+πn,n*Z |y=√cos2x/1+sinx|
21●–π/4+πn,n*Z |2sinx+cosx=1|
21●(x+1)²ex y=(x²+1)ex.
21●√x²–1+C