BEHAVIOUR OF GRADIENT BETWEEN TWO POINT
-Lets two points be which can be used to form the line AB.
(i) If , and the line increase from left to right imply positive slope.
(ii) If the line decrease from right to left imply slope.
(iii) If the line is horizontally with zero gradient
(iv) If the line is vertical with infinity gradient
COLLINEAR POINTS
– – Are point which lie on the same straight line
Where,
A, B, and C are collinear.
– – The condition of collinear points have the same slope/ gradient
Note:
If A (); B and C are collinear then the area of = 0.
Example 1
1. 1.Determine the value of K such that following points are collinear:-
a) and
b) and
2. Show that the points , and are collinear.
3. The straight line Cut the curve at P and Q. Calculate the length PQ.
4. If A and B are products of OX and OY respectively. Show that xy=16. If the area of is 8 units square.
Solution:
A B, C
For collinear point
2. Give
; B C
Alternatively
Since the area of ΔABC is 0 unit hence the points are collinear.
3. Given
4. Given
Since
Area of ΔOAB = 8 square units
Then,
5. If and are the collinear of midpoint of the line forming the points and show that, x-y+1=0.
Solution
M.P = (x, y)
A and B
Required