Now that we have already proven the derivative rules for sine and cosine, we can use them with a clever application of the Quotient Rule to derive the derivative rules for tangent and secant. Duration: 7:01

Finding tangent lines, horizontal or otherwise, is one of the more common things we do with derivatives. Now we have the opportunity to perform that mundane task with trigonometric functions. Duration: 15:01

Remember taking powers of the square root of negative one? Well, taking 29 derivatives of sine works on a similar, cyclical level. Duration: 3:56

For this final video on simple harmonic motion, make Edgar Allan Poe proud by imagining a sharpened sickle at the end of that pendulum. No matter how sharp it is or who might be chained up underneath it, the motion of that pendulum can be modeled by a sinusoid. As can its velocity and acceleration. Duration: 9:50