Tg 495гр *cos(-660гр )

Tg 495гр *cos(-660гр )

  • tg495*cos660

    tg495=tg(2*180+135)=tg 135=tg(180-45)=-tg45=-1

    cos(-660)=cos660=cos(360+300)=cos300=cos(360-60)=cos60=1/2

    -1*1/2=-0.5

  • tg 495=tg(360+135)=tg135=tg(-45)=-1/2;

    cos(-660)=cos(60)=1/2.

    tg 495гр.*cos(-660гр.)= -1/(22)