a: the act of describing a thing by giving its differentia b: the enhancement of microscopically visible differences between tissue or cell parts by partial selective decolorization or removal of excess stain (as in regressive staining) c: the development of a discriminating conditioned response with a positive response to one stimulus and absence of the response on the application of similar but discriminably different stimuli
a: modification of different parts of the body for performance of particular functions; also: specialization of parts or organs in the course of evolution b: the sum of the developmental processes whereby apparently unspecialized cells, tissues, and structures attain their adult form and function—compare determination 2
Mathematical process of finding the derivative of a function. Defined abstractly as a process involving limits, in practice it may be done using algebraic manipulations that rely on three basic formulas and four rules of operation. The formulas are: (1) the derivative of xn is nxn 1, (2) the derivative of sin x is cos x, and (3) the derivative of the exponential function ex is itself. The rules are: (1) (af + bg) = af + bg, (2) (fg) = fg + gf, (3) (f/g) = (gffg)/g2, and (4) (f(g)) = f(g)g, where a and b are constants, f and g are functions, and a prime () indicates the derivative. The last formula is called the chain rule. The derivation and exploration of these formulas and rules is the subject of differential calculus. See alsointegration.