Maths GCSE

1. Find two accurate points and complete the triangle

2. Find the change in x and the change in y

3. Use the formula         ( GRADIENT = CHANGE IN Y / CHANGE IN X )

4. Check the sign's right   

(If the line slopes uphill, then it's positive. If the line slopes downhill, then it's negative)

REMEMBER the equation of a straight line is y = mx + c where m is the gradient and c is the y intercept.

Parallel lines have the same value of m (the same gradient) but have different intercepts

E.g. y = 2x + 3, y = 2x and y = 2x - 4

The gradients of two perpendicular lines multiply to give -1

E.g. If the gradient of the first line is m, the gradient of the other line will be -1/m, beacuse m x -1/m = -1

A LINE is straight and CONTINUES TO INFINITY in both directions

A LINE SEGMENT is just part of a line - it has TWO END POINTS