Сум всех двухзначн чисел)

2●π/2(2π+1) n*Z(–1)k π/6+πk,k*Z ( cosx=sin2x )

2●π/2+2πn; (–1)n+1π/6+πn; {cos2x=sin(π+x)

2●π/4+2πn, n*z |sinx+cosx=√2|

2●π+2πn; n*z |cos(π+x)=sinπ/2|

2●π+πn,n*Z

2●2xcos²

2●πn, n*Z; ±π3+2πк |sin2x=sinx|

2●πn/2≤x<π/4+πn/2,n*Z | у=√tg2x|

2●πn≤x<π/2+πn,n*Z |y=√sin2x/cosx|

2●х=πn, х=–π/2+2πn... |f(x)=sin2x +sinx |

2●х=±π/3+2πк, к*Z |f(x)=sinx-x/2|

2●х=0; х=π/2+πк |f(x)=xsinx+cosx|

2●2x+sin2x/4+С |f(x)=cos²x|

2●х=4 |у=√2 и у=2|

2●b=π–2a/2