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
How to differentiate a non-differentiable function
Further Maths Interest - Weierstrass Function
Continuous Everywhere but Differentiable Nowhere | I have no idea why I picked this blog name, but there's no turning back now
In particular, any differentiable function must be continuous at every point in its domain.
Theory and Applications of Differentiable Functions of Several Variables by S. M. Nikolskii Download
non differentiable function
Dirichlet’s function is nowhere continuous and nowhere differentiable. It is also nowhere Riemann integrable since its upper integral and lower integral do not equal anywhere.
When is a function NOT differentiable. (Video from Khan Academy)
My Introduction to Trigonometry Unit for Geometry | Continuous Everywhere but Differentiable Nowhere