Lagrange's notation for differentiation is the notation for differentiation devised by Joseph Louis Lagrange. Lagrange proposed the notations:
- f''(x) for the first derivative
- f''(x) for the second derivative
- f'''(x) for the third derivative
- f(n)(x) for the nth derivative (n > 3)
Expressed in terms of Leibniz's notation for differentiation we have:
Sometimes Lagrange's notation is more useful than Leibniz's, for example when calculating the derivative at a point.
In Lagrange's notation, if you know f(x) and you want to calculate f '(x) at a point k, you would write: