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Coordinate Geometry
- The equation of a straight line can be written as y = mx + c, where m is the gradient and c is the intercept with the vertical axis.
- The gradient of a line passing through the points (x1,y1) and (x2,y2) is (y2 -y1) / (x2 -x1).
- The equation of the straight line with gradient m that passes through the point (x1, y1) is y-y1 =m(x-x1).
- Lines are parallel if they have the same gradient.
- Two lines are perpendicular if the product of their gradients is -1.
- If the gradient of a line is m, then the gradient of a perpendicular line is - 1/m.
- The midpoint of the line joining the points (x1, y1) and (x2, y2) is ((x1+x2)/2,(y1+y2)/2).
![broken image](http://custom-images.strikinglycdn.com/res/hrscywv4p/image/upload/c_limit,fl_lossy,h_9000,w_1200,f_auto,q_auto/4936730/190152_292015.png)
- The distance between the points with coordinates (x1,y1) and (x2,y2) is √(x2 -x1)^2 + (y2 -y1)^2.
- The equation of a circle centre (a, b) with radius r is (x-a)^2 +(y-b)^2 =r^2 .
![broken image](http://custom-images.strikinglycdn.com/res/hrscywv4p/image/upload/c_limit,fl_lossy,h_9000,w_1200,f_auto,q_auto/4936730/361823_421337.png)
When it comes to AS/A-level Maths, do you know how to find the point of intersection of lines?
![broken image](http://custom-images.strikinglycdn.com/res/hrscywv4p/image/upload/c_limit,fl_lossy,h_9000,w_1200,f_auto,q_auto/4936730/213725_977735.png)
That's the end of the topic!
![broken image](http://custom-images.strikinglycdn.com/res/hrscywv4p/image/upload/c_limit,fl_lossy,h_9000,w_1200,f_auto,q_auto/4936730/596919_420905.jpeg)
Drafted by Bonnie (Mathematics)