Coordinate Geometry

Question 1

How do you find a PARALLEL line?

Answer 1

A parallel line has the same GRAD as the line in the question. For example, y = 2x - 7 and y = 2x + 3 are parallel

Question 2

How do you find the MIDPOINT of a line?

Answer 2

The midpoint can be found by adding the 2 x coordinates together and the 2 y coordinates together and dividing the totals by 2. For example, ( x1 + x2 / 2 ) + ( y1 + y2 / 2 )

Question 3

How do you find the GRADIENT of a line?

Answer 3

You can find the gradient of a line by using +- rise / run. For example, +- 6 / 8

Question 4

How do you find a PERPENDICULAR line?

Answer 4

To find a perpendicular line, you flip the gradient to a fraction and make it negative. If it is already negative, then you make it positive. For example, y = 2x + 7 and y = -1/2x + 7

Question 5

How do you find the Y INTERCEPT of a line?

Answer 5

You can find the Y intercept by using Y = mx + c. M is the gradient, you can find C ( the Y intercept ) by swapping x with one of the x coordinates and y with one of the y coordinates. For example, if I had y = 3x + c and (0 , 1) are my coordinates, I would have 1 = 3(0) + C. You then times 3 and 0 together to get 0, leaving you with 1 = 0 + C. This means that C = 1

Question 6

How do you find the LENGTH of a line?

Answer 6

To find the length of a line, you should first draw a sketch of the line. Once you have the difference between the two coordinates, you use Pythagoras to find the length. For example, if my two differences were 4 and 8, you would square them, add them together, and factorise the answer to get the length