Prelucrezi ecuatia
4sin²x+2sin x*cosx-3=o
3sin²x+sin²x+2sinxcosx-3=0
3*(sin²x-1)+sin²x+2sinxcosx=0
-3cos²x+sin²x+2sinx*cos x=0 pui conditia cos³x=/=0 adica x=/=(2k+1)[tex] \pi /2[/tex] si imparti prin cos²x
vei obtine
-3+tg²x+2tgx=0 fie y=tgx
y²+2y-3=0
y1=-3/2 deci tgx=-3/2 x= arctg(-3/2)+k[tex] \pi [/tex]
y2=1/2 y =arctg1/2+k[tex] \pi [/tex] unde k apartine Z
