Straight Line

Question 1

How do you calculate the distance between points?

Answer 1

The square root of (x2 - x1)^2 + (x2 - x1)^2

Question 2

How do you calculate the midpoint of a line?

Answer 2

(x1 + x2) , (y1 + y2)
_____ ______
2 2

= ( , )

Question 3

How do you calculate the gradient of a line with two points?

Answer 3

m = (y2 - y1) / (x2 - x1)

Question 4

How do you calculate the gradient of a line with an angle?

Answer 4

m = tano

where tan = opposite/adjacent

Question 5

How do you work out is a line is collinear?

Answer 5

work out the gradient of one line (m1)
work out the gradient of another line (m2)
write statement :
If m1 = m2 the lines are collinear and share a common point _
If m1 != m2 the lines are not collinear

Question 6

How do you calculate the gradient of perpendicular lines?

Answer 6

Find gradient of one line
m1 x m2 = -1
Flip fraction of gradient and change the sign

Question 7

What is a median?

Answer 7

Is a line connected to the midpoint of a line in a triangle

Question 8

How do you calculate a median?

Answer 8

find the midpoint of the line of relevance
find the gradient of median line
find equation of line

Question 9

How do you find an altitude?

Answer 9

Find perpendicular gradient
Use m1 x m2 to find vertex gradient
Find equation of the line

Question 10

What is a altitude?

Answer 10

A line that meets another at a right angle

Question 11

What is a perpendicular bisector?

Answer 11

Perpendicular bisectors are lines that cut through the midpoint of a line at right angles

Question 12

How do you find the equation of a perpendicular bisector?

Answer 12

Find midpoint
Find gradient
Use m1 x m2 to find gradient
Find equation

Question 13

How do you find the point of intersection?

Answer 13

Make y the subject in the equation
Either:
- let y=y
or 
- do a simultaneous equation

Question 14

What does concurrency mean?

Answer 14

That the lines pass through the same point