350 independent events if the probability that event B happens is the same, whether event A happens or not, then A and B are independent events xx inequality a relationship between two expressions that are not equal xx inscribe when you inscribe a polygon in a circle, every vertex is on the circle xx inverse proportion two quantities are in inverse proportion if, when one quantity increases the other quantity decreases in the same ratio xx irrational number a number on the number line that is not a rational number xx isometric paper paper covered with lines or dots that form congruent equilateral triangles xx line of best fit a line on a scatter graph that shows the relationship between the two sets of data xx linear function a function with a straight-line graph xx linear sequence a sequence of numbers in which the difference between consecutive terms is the same xx lower bound the smallest value that a rounded number could have been before it was rounded xx method of elimination a method for solving simultaneous equations when the number of xs or ys is the same, so you add or subtract the two equations to eliminate the xs or the ys xx method of substitution a method for solving simultaneous equations where you write one of the equations in the form ‘y = …’ or ‘x = …’ and then substitute this into the other equation xx midpoint the middle value in a class interval xx misleading information that leads you to an incorrect conclusion xx mutually exclusive events are mutually exclusive if only one of them can happen at one time xx non-linear sequence a sequence of numbers in which the difference between consecutive terms is not the same xx perfect square a perfect square is a number, or expression, that can be written as the product of two equal factors e.g. 3 × 3 = 9, x × x = x2 , (x + 1)(x + 1) = x2 + 2x + 1 xx plane of symmetry a line that divides a 3D shape into two congruent halves that are mirror images of each other xx prefix a set of letters that you put in front of a word xx Pythagoras’ theorem a relationship between the three sides of a right-angled triangle SAMPLE xx We are working with Cambridge Assessment International Education towards endorsement of this title. Original material © Cambridge University Press 2021. This material is not final and is subject to further changes prior to publication. ISBN_9781108783774.
351 quadratic sequence a sequence of numbers in which the second difference between consecutive terms is the same; the highest power in the nth term rule is 2 (squared) xx rational number any number that can be written as a fraction xx ray lines lines that start at a fixed point and continue forever xx recurring decimal in a recurring decimal, a digit or group of digits is repeated forever xx regular polygon a polygon where all the sides are the same length and all the interior angles are the same size xx relative frequency if an action is repeated, the relative frequency of a particular outcome is the fraction of times when that outcome occurs xx scatter graph a graph showing linked values of two variables, plotted as coordinate points, that might or might not be related xx scientific notation the same as standard form xx sector a part of a circle formed by two radii and the part of the circumference joining their ends simultaneous equations two or more equations, each containing several variables xx solution set the set of numbers that form a solution to a problem xx solve calculate the value of any unknown letter(s) in an equation xx standard form a way of writing very large or very small numbers in the form a × 10b , where 1 ⩽ a < 10 and n is an integer xx strategies methods xx subject of a formula the letter that is on its own on one side (usually the left) of a formula xx surd an irrational square root or cube root xx terminating decimal a decimal number that does not go on forever xx tonne a unit of mass such that 1 tonne = 1000 kilograms xx upper bound the largest value that a rounded number could have been before it was rounded xx SAMPLE We are working with Cambridge Assessment International Education towards endorsement of this title. Original material © Cambridge University Press 2021. This material is not final and is subject to further changes prior to publication. ISBN_9781108783774.