Today in class we did some more practice/considerations with identities. We learned about EXTRANEOUS roots.- "they are answers that look good on paper but practically don't make sense".
When we are doing our questions, all solutions must be checked for validity. In an equation you want to bring everything to one side, and when you have a question like cos(x)+1=sqare root thre sin(x), you always want to sqare both terms to get rid of the radical.