Vandermonde, Alexandre-Théophile, 636

Variable(s), 2

• dependent and independent, 185, 215

Variable costs, 227

Variation, 403–412

• constant of, 404

• direct, 404–406

• inverse, 406–407

• joint and combined, 407–409

Variations of sign, 367–368

Verhulst, Pierre François, 475, 482

Verhulst model, 475, 482

Vertex(ices)

• of an ellipse, 676, 678

• of a hyperbola, 691, 692

• of a parabola, 319, 322, 662

• of a right circular cones, 659

• of the solution set of a system of inequalities, 563

Vertical asymptotes, of a rational function, 386–387, 389

Vertical ellipses, 678

Vertical lines, equations of, 203

Vertical-line test, 222

Vertical shifts of graphs, 263–266

Vertical stretching/compressing, 269–271

Volume, of a wine barrel, 332, 345