“Teach A Level Maths” Vol. 1: AS Core Modules 1: Distance between two points. Thursday, 02 August 2018 © Christine Crisp

Using Pythagoras’ theorem: This square root is called a surd.

A formula for the length of the line joining A to B Using Pythagoras’ theorem:

e.g. Find the length of the line joining the point to Solution: This can be simplified: 25 is a perfect square, so can be square rooted

Exercise Find the length of the line joining the point to Solution:

“Teach A Level Maths” Vol. 1: AS Core Modules 2: Finding the mid-point of a line segment. Thursday, 02 August 2018 © Christine Crisp

Further Practice: Exercise 1A Page 5/6 Complete all 6 questions in class, finishing for homework if necessary.

The mid-point is the average of the end points: M X The mid-point is the average of the end points:

A formula for the Mid-Point of AB M X The mid-point is the average of the end points: or

Exercise Find the mid-point, M of the line joining to Solution:

SUMMARY The mid-point, M, of the line joining to is the average of the end points. The length of the line joining to is:

Further Practice: Exercise 1B Page 7/8 Complete all 6 questions in class, finishing for homework if necessary.

The following slides contain repeats of information on earlier slides, shown without colour, so that they can be printed and photocopied. For most purposes the slides can be printed as “Handouts” with up to 6 slides per sheet.

SUMMARY The mid-point, M, of the line joining to is the average of the end points. The length of the line joining to is:

Solution: e.g. Find the mid-point, M of the line joining to

25 is a perfect square, so can be square rooted Solution: e.g. Find the length of the line joining the point to