Solving Trig Equations

On Friday I was away, so it was a huge relief to find out that todays class was going to be pretty much a repeat of Fridays class. We did alot of example questions showing how to solve equations using our charts and the 6 trig functions. He also taught us how to go about our accelerated math. I understood how to solve the equations, but when I use my chart to find the answers, some of them would be wrong. Thats when I realized half my chart is backwards. So that explained why I was so confused why I couldn't get the right answer.