Eduqas GCSE Mathematics key terms

For an acute angle in a right-angled triangle, the ratio of the adjacent side to the hypotenuse: $\cos\theta=\frac{\text{adjacent}}{\text{hypotenuse}}$.

A relationship connecting three side lengths and one angle in any triangle: $a^2=b^2+c^2-2bc\cos A$, where side $a$ is opposite angle $A$.

A particular example for which a general claim is false. One counter-example is enough to disprove a claim about every case.

A value of $x$ where a quadratic expression equals zero. These values locate the boundaries used when solving a quadratic inequality.

The two-dimensional shape exposed by a slice through a solid. For prism volume calculations, use a cross-section parallel to the matching end faces.

A number obtained by multiplying an integer by itself three times, such as $4^3=64$.

The number that gives a specified value when cubed. For example, $\sqrt[3]{125}=5$ because $5^3=125$.

A function of the form $y = ax^3 + bx^2 + cx + d$, with $a \neq 0$, whose highest power of $x$ is 3.

The running total of frequencies up to a particular value.

A part of the outside of a solid that bends rather than lying flat, such as the outside of a sphere.

A quadrilateral whose four vertices all lie on the circumference of one circle.

The number of digits shown after the decimal point.

A numerical method that searches using successively smaller decimal steps to narrow an interval containing a solution.

The bottom number in a fraction; in $\frac{3}{5}$, the denominator is 5.

Mass per unit volume: $\text{density}=\frac{\text{mass}}{\text{volume}}$. Common units are g/cm³ and kg/m³.

Events for which knowing that one has occurred changes the probability of the other.

A reduction in an item's value over time, often modelled as a repeated percentage decrease.

An arrangement of numbers from largest to smallest.

A line segment joining two non-adjacent vertices of a polygon.

A chord that passes through the centre of a circle. Its length is twice the radius: $d=2r$.

An expression in which one squared quantity is subtracted from another, factorised using $A^2-B^2=(A+B)(A-B)$.

A relationship in which one quantity is a constant multiple of another: $y=kx$. For non-zero $x$, $\frac{y}{x}=k$.

Numerical data that can take only particular, separate values, such as the whole-number count of people in a room.

The pattern of values in a data set, including where values are concentrated and how widely they are spread.

A boundary where surfaces of a solid meet. An edge can be straight, as on a cube, or curved, as around the circular base of a cone.

An individual item belonging to a set.

A two-dimensional view of a three-dimensional object, seen directly from the front or a side.