English for Students of Mathematics.

number: A number with no associated units. Acute angle: An angle with degree measure less than 90. Addition: The process of finding the sum of two numbers, which are called addend and the augend symbolised using two vertical straight lines ( |5| ). Also called (sometimes both are called the addend). Algorithm: Any mathematical procedure or instructions involving a set of steps to solve a problem. Arctan: The inverse of the trigonometric function tangent shown as arctan(x) or tan-1(x). It is useful in vector conversions and calculations Arithmetic mean: M = (x1 + x2 + .... xn) / n (n = sample size). Arithmetic sequence: A sequence of numbers in which each term (subsequent to the first) is generated by adding a fixed constant to its predecessor. Associative property: A binary operation (*) is defined associative if, for a*(b*c) = (a*b)*c. For example, the operations addition and multiplication of natural numbers are associative, but subtraction and division are not. Asymptote: A straight line that a curve approaches but never meets or crosses. The curve is said to meet the asymptote at infinity. In the equation y = 1/x, y becomes infinitely small as x increases but never reaches zero. Axiom: Any assumption on which a mathematical theory is based. Average: The sum of several quantities divided by the number of quantities (also called mean). Avogadro's number: The number of molecules in one mole is called Avogadro’s number (approximately 6.022 × 1023 particles/mole). Binary operation: An operation that is performed on just two elements of a set at a time. Binomial distribution: A probability distribution that summarizes the likelihood that a value will take one of two independent values under a given set of parameters or assumptions. Butterfly effect: In a system when a small change results in an unpredictable and disproportionate disturbance, the effect causing this is called a butterfly effect. Calculus: Branch of mathematics concerned with rates of change, gradients of curves, maximum and minimum values of functions, and the calculation of lengths, areas and volumes. It involves determining areas (integration) and tangents (differentiation), which are mutually inverse. Also called real analysis..