a: the product of the derivative of a function of one variable by the increment of the independent variable
b: a sum of products in which each product consists of a partial derivative of a given function of several variables multiplied by the corresponding increment and which contains as many products as there are independent variables in the function
: a difference between comparable individuals or classes <a price differential>; also: the amount of such a difference
a: a drivetrain gear assembly connecting two collinear shafts or axles (as those of the rear wheels of an automobile) and permitting one shaft to revolve faster than the other
In calculus, an expression based on the derivative of a function, useful for approximating certain values of the function. The differential of an independent variablex, written x, is an infinitesimal change in its value. The corresponding differential of its dependent variable y is given by y = f(x + x) f(x). Because the derivative of the function f(x), f(x), is equal to the ratio as x approaches zero (seelimit), for small values of x, yf(x)x. This formula often enables a quick and fairly accurate approximation to be made for what otherwise would be a tedious calculation.