Question

sin^2x-4sinx*cosx + 3cos^2x=0

Answer 1

sin^2x - 4sinxcosx + 3cos^2x = 0       /cos^2x ≠ 0
tg^2x - 4tgx + 3 = 0
1)  tgx = 1
x1 = π/4 + πn, n∈Z
2) tgx = 3
x2 = arctg3 + πk, k∈Z