Question

sin(x)sec(x)-2sin(x)=0
solved over {0,3pi}

Answer 1

sin(x)sec(x)-2sin(x)=0
sinx(secx - 2) = 0
sinx = 0 or secx = 2

if sinx = 0 , x = 0, π, 2π, 3π for your given domain
if secx = 2, then
cosx = 1/2
x = π/3, 5π/3, 7π/3