Verified answer

sin377°=sin(360°+17°)=sin17°

cos407°=cos(360°+47°)=cos47°

sin377°-√3cos17°=sin17°-√3cos17°=2*((1/2)*sin17°-(√3/2)cos17°)=

=2*(sin30°sin17°-cos30°cos17°)=-2*(cos30°cos17°-sin30°sin17°)=-2cos(30°+17°)=-2cos47°

-2cos47°/cos47°=-2

Ответ -2.