Question

Rezolvați in R ecuația sin x tg x-cosx=0

Answer 1

Sinusul si cosinusul sunt intodeauna egale la 45 de grade

Answer 2

Domeniul  de  existenta   al ecuatiei 
x≠(2k+1)π/2 -in  aceste   puncte tangenta nu  este definita
cosx*(sinx/cosx*tgx-1)=0
cosx*(tg²x-1)=0=>
cosx=0  si  (tg²x-1)=0
c0sx=0 => x=(2k+1)π/2∉domeniului  de  existenta stabilit anterior
tg²x-1=0=>
tg²x=1
tgx=+/1
tgx=1=>x=π/4
solutia generala
x1=π/4+/-kπ   k∈Z
tgx=-1
x=5π/4
x2=5π/4+/-kπ
x={π/4+/-kπ}U{5π/4+/-kπ}={{π/4+/-kπ}