Question

5sin^2x-11cisx^2+3=0

Answer 1

5sin²x-11cos²x+3 = 0
5sin²x-11(1-sin²x)+3 = 0
5sin²x-11+11sin²x+3 = 0
16sin²x-8 = 0
16sin²x = 8
sin²x = 1/2
sin x = 1/√2 и sin x = -1/√2
sin x = 1/√2 → x = (-1)^n·π/4+πn
sin x = -1/√2 → x = (-1)^n·5π/4+πn, n∈Z