I'm trying to teach myself trig and have done fine until this question under "Solve Sinusoidal Equations." I looked at the hints and don't get it at all. How and why did they introduce pi/3 in step 2 of the solution? Where did that come from?
I got it all the way to inverse cos 0.5= on one side, but where that next step came from introducing pi/3, I have no idea. Thanks!