I can't verify those 3 problems.
1. Sin^2a + Tan ^2a + Cos ^ 2 a = sec ^ 2 a.
2. (1-cosx)/1+cosx = ( cot x - csc x ) ^2
3. cots + tans = sec s csc s
thx for the help.
What have you tried?
Did you go with the tried and true default backup plan and change everything to sine and cosine?
Of course, I would NOT do that with the first one. That one is just staring at you. Reach out and grab it. Quick!! It's getting away!
This should ring some bells...