ALGEBRA      DERIVATIVES      INTEGRALS      SERIES/SEQUENCES      TRIG       
   

   DERIVATIVES > Introduction        

The primary operation in differential calculus is finding a derivative. This table lists derivatives of many functions. In the following, f and g are functions of x, and c is a constant. The set of real numbers is assumed. These formulas are sufficient to differentiate any elementary function.

Definitions of the Derivative:
df / dx = lim (dx -> 0) (f(x+dx) - f(x)) / dx (right sided)
df / dx = lim (dx -> 0) (f(x) - f(x-dx)) / dx (left sided)
df / dx = lim (dx -> 0) (f(x+dx) - f(x-dx)) / (2dx) (both sided)

(d/dx)(integral)(a to x) f(t) dt = f(x) (Fundamental Theorem for Derivatives)


(d/dx)c f(x) = c
(d/dx)f(x) (c is a constant)

(d/dx) (f(x) + g(x)) = (d/dx) f(x) + (d/dx) g(x)

(d/dx) f(g(x)) = (d/dg) f(g) * (d/dx) g(x) (chain rule)

(d/dx) f(x)g(x) = f'(x)g(x) + f(x)g '(x) (product rule)

(d/dx) f(x)/g(x) = ( f '(x)g(x) - f(x)g '(x) ) / g2(x) (quotient rule)


Partial Differentiation Identities

if f( x(r,s), y(r,s) )

df / dr = df / dx * dx / DR + df / dy * dy / DR
df / ds = df / dx * dx / Ds + df / dy * dy / Ds

if f( x(r,s) )

df / DR = df / dx * dx / DR
df / Ds = df / dx * dx / Ds

directional derivative

df(x,y) / d(Xi sub a) = f1(x,y) cos(a) + f2(x,y) sin(a)
(Xi sub a) = angle counterclockwise from pos. x axis.
- DERIVATIVES -
  • Introduction


  • General functions


  • Simple functions


  • Exponential and logarithmic functions


  • Trigonometric functions


  • Hyperbolic functions

  • More