The text "So, you think you know how to take derivatives?" surround by derivatives.

You may think you mastered derivatives after learning a few simple rules, but you could be bewildered if you are faced with more complicated functions like a matrix determinant (what is a derivative “with respect to a matrix”?), the solution of a differential equation, or other huge practical calculations.  We address such topics by re-emphasizing what a derivative really is — linearization — and refocusing differential calculus on the linear algebra at its heart. (Image courtesy of Prof. Steven G. Johnson.)