Rachel
About
Khan Academy on a Stick
Cosine addition identity example
Angle addition formulas
Applying angle addition formula for sin
Angle addition formula with cosine
Another example using angle addition formula with cosine
Sine of non special angle
Cosine addition identity example
Double angle formula for cosine example
Your browser does not support Flash or HTML5 video. You can:
upgrade your browser
install Flash
try this direct link
If the above player doesn't work,
try this direct link
.