Solving Using Reals

Well today we did a mental math. Holy crap. I got 2 out of 5, which was actually pretty good compared to how the whole class did. We aren't allowed to scribble. My whole life I have scribbled for mental math. It's so hard without being able to scribble! We also learned how to solve trig equations using an infinite domain. Surprisingly, I understood the concept. I don't know if I understand enough to actually do my homework, but, I'll try. This class goes by way too fast for my brain.