1) 3cos(7π)\4+2sin(3π)\4-sin(-9π)\4+7cos(13π)\2=3·cos(2π-π\4)+2·sin(π-π\4)+sinπ\4+7·cosπ\2=3·cosπ\4+2·sinπ\4+√2\2+7·0=3·√2\2+2·√2\2+√2\2+0=3√2
2)2sin(-5π)\6+11cos(-7π)\3+sin(7π)\6-8cos(2π)\3=-2sin(π-π\6)+11cosπ\3+sin(π+π\6)-8cos(π-π\3)=-2·sinπ\6+11·1\2-sinπ\6+8·cosπ\3=-2·1\2+11·1\2-1\2+8·1\2=8