The Taylor Series of a real or complex-valued function f(x) that is infinitely differentiable at a real or complex number a is the power series; this serves as a way to approximate a polynomial
Further Maths Interest - Weierstrass Function
How to differentiate a non-differentiable function
Differentiable function - Wikipedia
Continuous Everywhere but Differentiable Nowhere | I have no idea why I picked this blog name, but there's no turning back now
When is a function NOT differentiable. (Video from Khan Academy)
Theory and Applications of Differentiable Functions of Several Variables by S. M. Nikolskii Download
My Introduction to Trigonometry Unit for Geometry | Continuous Everywhere but Differentiable Nowhere
In particular, any differentiable function must be continuous at every point in its domain.
Great blog. Love this post on his process for writing recommendation letters for students.