Question

sin(-7п) +2cos(31п/3)-tg(7п/4)

Answer 1

$sin(-7 pi )+2cos( frac{31 pi }{3} )-tg( frac{7 pi }{4} )=\\ =-sin(6 pi + pi )+2cos(10 pi + frac{ pi }{3} )-tg( 2 pi -frac{ pi }{4} )=\\ =-sin pi +2cosfrac{ pi }{3}+tgfrac{ pi }{4} =0+2cdot frac{1}{2} +1=1+1=2$