sina*cosB+cosa*sinB+sina*cosB-cosa*sinB/sina*cosB+cosa*sinB+sina*cosB-cosa*sinB=sina*cosB+sina*cosB/sina*cosB+sina*cosB=2sina*cosB/2sina*cosB=1 вроде так)
sina*cosB+cosa*sinB+sina*cosB-cosa*sinB/sina*cosB+cosa*sinB+sina*cosB-cosa*sinB=sina*cosB+sina*cosB/sina*cosB+sina*cosB=2sina*cosB/2sina*cosB=1 вроде так)