Straight Line

Question 1

The Distance Formula

Answer 1

d= ./*(x2-x1)^2+(y2-y1)^2 units

Question 2

The Midpoint Formula

Answer 2

(x1+x2 over 2) (y1+y2 over 2)

Question 3

The Gradient Formula

Answer 3

M=tan0 (theta) OR y2-y1 over x2-x1

Question 4

Rule of Colinearity

Answer 4

If gradients of three points are the same, points are colinear.

Question 5

Rule of Perpendicular Lines

Answer 5

If m1 x m2 = -1, lines are perpendicular.

Question 6

Converting Gradient To Perpendicular

Answer 6

Change the sides, change the ±. m1 x m2 = -1

Question 7

Find Equation Of The Median

Answer 7

Calculate the midpoint of the relevant line.
Calculate gradient of line between MP and opposite vertex.
Put in form y-b=m(x-a).

Question 8

Find Equation Of The Altitude

Answer 8

Calculate gradient of side perpendicular to altitude.
Calculate gradient of altitude using perpendicular rule.
Find equation using perpendicular point and gradient.

Question 9

Find Equation Of Perpendicular Bisector

Answer 9

Calculate midpoint of line being segmented.
Calculate gradient of this line, then perpendicular.
Find equation of bisector using perpendicular line and MP.

Question 10

Find Points of Intersection On Lines

Answer 10

Work it as a simultaneous equation, display as co-ordinates (x,y).

Question 11

Concurrency

Answer 11

Lines are concurrent if they all pass through the same point.

Question 12

If m=0/1

Answer 12

M=0 therefore the equation is y=c (y intercept).

Question 13

If m=1/0

Answer 13

M=undefined. Go to x co ordinate equation is x=1