Deriving Double Angle and Half Angle Identities
cos(2A), sin(2A), tan(2A): This video derives the double angle identities for cosine, sine, and tangent, and provides examples using the formulas.
Deriving the Half Angle Identities for cosine, sine, and tangent: http://www.youtube.com/watch?v=S9XkwZ4n3b4
Prove Trig Identity 9: http://www.youtube.com/watch?v=88r_tIpfmMk
We verify two identities using the double angle and half angle identities.
Computing using Trig Identities:Â
Compute using Trig Half Angle Identity 1: http://youtu.be/qtA0lumhQeE
Compute using Trig Half Angle Identity 2 (The intro explains what will be computed on each video, and which formula will be used.)
Compute using Trig Half Angle Identity 2 Intro: http://youtu.be/FoqtIF1gC7s
Compute using Trig Half Angle Identity 2A: http://youtu.be/39Zi7Vpl0gM
Compute using Trig Half Angle Identity 2B: http://youtu.be/4GZ3_AKQojI
Compute using Trig Half Angle Identity 2C: http://youtu.be/QDZZaYdBInQ
Compute using Trig Half Angle Identity 2D: http://youtu.be/pyHcEaz7hDI
Compute using Trig Half Angle Identity 2E: http://youtu.be/X92QwUmCWzU
Compute using Trig Half Angle Identity 2F: http://youtu.be/zTj_aPNFN90
Compute using Trig Half Angle Identity 3: http://youtu.be/U4mgi6Sj7yw
Computing using Trig Identities: These are problems where you are given some info, and then need to compute something else. For example, you might need to compute sinA if you know the cos2A, etc.
Computing 1: http://youtu.be/B2A-mjkw_n8
Computing 2: http://youtu.be/ybAob-dGHQE
Computing 3: http://youtu.be/KjLsQDBEDM4
Computing 4: http://youtu.be/SE7J6pNfWZ0
Computing 5: http://youtu.be/9OM7INfptSo