Question

определите знак cos 305° и tg(-6п/5)

Answer 1

$cos, 305=cos(360-55)=cos(-55)=cos55 textgreater 0,; \\tak; kak; ; ; 0^circ textless 55^circ textless 90^circ \\\tg(- frac{6pi }{5})=-tgfrac{6pi}{5}=-tg(pi +frac{pi}{5})=-tgfrac{pi}{5} textless 0;\\tak; kak; ; ; 0 textless frac{pi}{5} textless frac{pi }{2} ; ; Rightarrow ; ; tg frac{pi}{5} textgreater 0; ; Rightarrow ; ; -tg frac{pi}{5} textless 0; .$