Quotient rule for derivative of tan x : Khan Academy on a Stick

Khan Academy on a Stick

Product and quotient rules

Derivatives of sin x, cos x, tan x, e^x and ln x
The product rule for derivatives
Product rule for more than two functions
Quotient rule from product rule
Quotient rule for derivative of tan x
Using the product rule and the chain rule
Product rule
Quotient rule and common derivatives
Equation of a tangent line

If the above player doesn't work, try this direct link.