Dandelin, Germinal Pierre, 660

Dandelin spheres, 660

Dantzig, George, 570

Decay

• exponential, 437–438, 469, 741

• linear, 436–437

Decibel scale, 493–495

Decimals

• converting to a quotient, 3–4

• converting to scientific notation, 26

• terminating and nonterminating, 3

Decomposition, of a function, 288

Decreasing functions, 235–237

Deepwater Horizon, 281

Deer population, 185

Definitions, recursive, 226

Degenerate conic sections, 660

Degrees

• of a monomial, 30–31, 37

• of a polynomial, 31

• of a polynomial function, 332, 333

• of a power function, 334–335

Denominators, 13, 50

• least common, 54–56

• rationalizing, 67

Dependent systems of linear equations, 530, 531

Dependent variables, 185, 215

Depressed equations, 358–359

Descartes, René, 202

• background information on, 176

• coordinate plane discovery by, 175

Descartes’s Rule of Signs, 367–368

Descending order, 31

Determinants, 636–647

• Cramer’s Rule and, 640–644

• minors and cofactors and, 637–638

Devil’s Triangle, 144, 147–148

De Vita Propria (Cardano), 376

Dice, rolling, 780

Difference(s). See also Subtraction

• binomial, squaring, 35–36

• of cubes, factoring, 45–46

• of functions, 282

• of squares, factoring, 44–45

• of terms, product of sum of terms and, 36–38

Difference quotients, 243–244

Digits, number of, logarithms and, 466–467

Direction, of an inequality, 146

Directrix, of a parabola, 662

Direct variation, 404–406

• with powers, 405–406

Discriminant, 112–113, 126–127

Distance formula, 178–180

Distinguishable permutations, 773–774

Distributive property of real numbers, 12

Dividends, 551, 554

Division. See also Quotient(s)

• of complex numbers, 123–125

• of fractions, 14

• of polynomials. See Division of polynomials

• of rational expressions, 52–53

• of real numbers, 13–14

• synthetic, 355–356

Division Algorithm, 352–354

Division of polynomials, 352–363

• Division Algorithm and, 352–354

• long division for, 353–354

• synthetic division for, 355–356

Domains

• of an inequality, 145

• of composite functions, 286–288

• of exponential functions, 426

• of functions, 216, 220–221, 223, 282, 283–284

• of logarithmic functions, 447–448

• of a rational expression, 50–51

• of a rational function, 385–386

• of a relation, 217

• of a variable in an equation, 81–82

• of a variable in an inequality, 145

Double roots, 108

Drug bioavailability, 215, 225–226

Drug research and development, profit from, 41, 45–46

Drug testing, false positives in, 50, 51