Question

Докажите тождество:1-sint/cost=cost/1+sint

Answer 1

(1-sint)/cost = cost/(1+sint)
(1-sint)(1+sint)= $(cost)^{2}$
1-$( sint)^{2}$ = $(cost)^{2}$
1=$(cost)^{2}$ + $( sint)^{2}$
1=1