Question

sin(180°+a)-cos(90°+a) ​

Answer 1

Ответ:

sin180*cos a-cos180*sin a+cos 90*cos a-sin90*sina=

=0*cos a-(-1)*sin a+0*cos a-1*sina=sina-sina=0

Объяснение:

Answer 2

$\displaystyle\bf\\Sin\Big(180^\circ+\alpha \Big)-Cos\Big(90^\circ+\alpha \Big)=-Sin\alpha -\Big(-Sin\alpha \Big)=\\\\=-Sin\alpha +Sin\alpha =0$