Question

Вычислить:
2tg (-π/4) ctg (-π/4) +3sin (-π/2) +5cos (-π/6)

Answer 1

$2tg (- frac{ pi }{4} ) ctg (-frac{ pi }{4}) +3sin (-frac{ pi }{2}) +5cos (-frac{ pi }{6})=$$=2tg frac{ pi }{4}*ctgfrac{ pi }{4} -3sinfrac{ pi }{2} +5cosfrac{ pi }{6}=2*1-3*1+5* frac{ sqrt{3} }{2} =-1+2.5 sqrt{3}$