Higher Order Derivatives:
The derivative ƒ' (x) of a function y = ƒ(x) is known as the first derivative of ƒ(x) at x. consider, the function ƒ' (x) is itself differentiable at x. Then the function d/dxƒ' (x) is known as the second derivative of ƒ(x) at x. It is shown as ƒ"(x) or ƒ(2) (x) or
or y2. In common, the nth derivative of ƒ(x), denoted ƒ(n)(x), is described as

The order sequence of the nth derivative of y = ƒ(x) are
or yn or Dny.
The process of searching out the nth derivative (n ≥ 2) of a function is known as successive differentiation.
Example: If y = tan-1 x, prove that
