See chain rule for differentiation and chain rule for higher derivatives for background information.
See Quiz:Differentiation rules for a quiz on all the differentiation rules together.
Suppose and are both twice differentiable functions everywhere on . Which of the following is the correct formula for , the second derivative of the composite of two functions?
Suppose are everywhere differentiable functions from to . What is the derivative where denotes the composite of two functions? In other words, .