Question

Sin(-810)+cos(-900)+tg(-395)ctg575

Answer 1

$sin(-810^circ)+cos(-900^circ)+tan(-395^circ)cot575^circ=\=-sin(810^circ)+cos(900^circ)-tan(395^circ)cot575^circ=\=-sin(2cdot360^circ+90^circ)+cos(2cdot360^circ+180^circ)-\-tan(360^circ+35^circ)cot(360^circ+215^circ)=\=-sin(90^circ)+cos(180^circ)-tan(35^circ)cot(215^circ)=\=-2-tan(35^circ)cot(180^circ+35^circ)=\=-2-tan(35^circ)cot(35^circ)=-2-1=-3$