Hi,

I just started with trig and trig proofs are like really hard for me, I just can't seem to understand them. This is the first question in my workbook..

it asks me to "Verify the statement is true for " and then "Prove the statement is an identity." Could someone please show me the steps on doing this? The right side I'm actually okay with but the left side, I don't know what to do with the "- 1s"

Oh, and any tips on how I can learn how to do these types of questions and eventually advance in trig proving, they would be really appreciated!