|  | All of the standard functions are differentiable 
                    except at certain singular points, as follows: Polynomials are differentiable for all arguments.
 A rational function
  is differentiable except where q(x) = 0, where the function 
                    grows to infinity. This happens in two ways, illustrated by  . Sines and cosines and exponents are differentiable everywhere 
                    but tangents and secants are singular at certain values. (where?)
 The inverse functions to powers such as x1/2 and 
                    x1/3 are differentiable where they are defined 
                    except where the functions they are inverse to have 0 derivative.
 |  |