Professor Dave Explains
What is a Derivative? Deriving the Power Rule
What is it to take the derivative of a function? Let's derive and define the power rule, so that we can take the derivative of simple polynomials.
Khan Academy
Khan Academy: Geometry: Language and Notation of the Circle
Formally defines a circle and different parts of a circle. Identifies the proper notation for naming different parts of a circle. [11:12]