The interquartile range is the difference between the upper quartile and the lower quartile of a dataset. It represents the range containing the middle 50% of the data
Two tangents from the same external point are equal in length
The angle formed by two tangents drawn from the same external point to the circle is twice the angle subtended at the center by the arc between the tangents
A pair of linear equations in which the variable appears in each equation, and the solution involves solving for the intersection point of the two lines.
percentage increase
A percentage increase is calculated by finding the amount of an increase as a fraction of the original value, then multiplying by 100.
surd
A value in the form of an expression containing a square root (e.g., √2, 3 + √2).
intercept
The point where a graph of a linear equation intersects the x-axis, giving the value of x when y is equal to zero.
gradient
The rate of change of a linear equation, calculated by dividing the difference in y-values by the difference in x-values.
quadratic formula
A formula used to solve quadratic equations in the form ax^2 + bx + c = 0, given by x = (-b ± √(b^2 - 4ac)) / 2a.
gradient formula
m = (y2 - y1) / (x2 - x1), where m is the gradient and (x1, y1) and (x2, y2) are two points on the line.