3+Khan+Video+Notes

=**Trigonometric Functions and Proofs**=

1st Video - SOH CAH TOA - Sine = Opposite / Hypotenuse - Cosine = Adjacent / Hypotenuse - Tangent = Opposite / Adjacent - These trigonometric functions are related to each other - Looking at the functions as opposite / hypotenuse for example can lead to ratios - Sin of theta / Cosine of theta = Tan theta

2nd Video - Tries to show a proof - Starts off with the formula Sin (alpha + beta) - Sin (alpha + beta) = line BC/ line AB - The terms cancel out bringing you back to the initial equation - Line BD + Line EF/ Line AB

3RD Video - Tried to come up with a third trigonometric proof - The function used is Cosine (alpha + beta) - The first equation equals line AC / line AB - Line AF – Line DE / Line AB - After the equation, you are left with cos(alpha) x cos(beta) – sin(alpha)/sin(beta)