The general equation of a line may be wriiten as (1) where m is the gradient andis the– intercept, or whereis again the gradient. We may be asked: Find the equation of the line which passes through the two pointsand we have to find the gradient We can then use either equation (1) in which […]

## The Distance Between Two Points

Suppose we want to find the length of the line between A and B in the diagram below. We draw a straight line between A and B, and make this rhe hypotenuse of a right angled triangle by drawing a horizontal line from A to a point directly below B and another line down from […]

## Scale Factors and Negative Enlargements

A ‘normal’ enlargement casts a ‘shadow’ of the shape, which may be larger or smaller than that shape to be enlarged. The scale factor k is positive, with the enlarged shape being k times as far from the centre of enlargement as the original shape. If the scale factor is more than one, the enlarged […]

## Compound Interest

If you invest money in a savings account at say 10% per year, typically you are paid compound interest. This means that as soon as the first instalment of interest is paid, you start getting paid interest on your interest. If you were to draw a graph of the amount of money in your account […]