These are task cards that I use in my Precalculus class when working with trigonometric identities. The product includes 28 questions along with the answers. The questions can be printed out with just one side (the question) or two-sided (question on front and answer on back). I usually print mine with the answers on the back so that they can check their work and know if they are right.
I have used this product in a couple of ways. First, I use it for them to work in pairs and practice simplifying the expressions. Each group would take a card and then rotate when time is called. Secondly, I have used this as a warm-up before we move on to verifying identities. I would give each student a card when they come in for them to complete as their warm-up and then switch cards with their partner and check answers when both questions are done.