Trigonometry - Find the exact values - Please show the formula and steps in getting the answer. I think we need to use half angle formula and sum and difference formula's to get the answers for those question.
Trigonometry : Double Angle Formula - I need to verify this expression and I'm stuck... should I divide both sides by 2 first? Please advise as to the proper steps to take in this verification.
Trigonometric identities - Use a half-angle identity to find each exact value of tan(195).
see attached.