Please have in mind that <span>sin(A - B) = sin(A)cos(B) - cos(A)sin(B) </span> So what we do is: <span>sin(3x)cos(x) - sin(x)cos(3x) = 0 => sin(3x - x) = 0 </span>
<span>sin(2x) = 0 </span>
<span>2x = 0, π, 2π, 3π, 4π </span>
<span>x = 0, π/2, π, 3π/2, 2π With this, even though not giving you all the answers, will help you greatly to get them. I know you will get the answers with no problems.</span>
