ответ:√2-2
Пошаговое объяснение:
sin(-7π/4)+cos(7π/4)+tg(15π/4)-ctg(-7π/4)=
(-sin(7π/4))+((cos(2π-π/4))+(tg(4π-π/4))+ctg(2π-π/4)=
sin(π/4)+cos(π/4)-tg(π/4)-ctg(π/4)=√2/2+√2/2-1-1=√2-2
