IGCSE Math Chapter 15 Gradient of two points

IGCSE Chapter 15 Straight Line
How to find gradient between two points

1. Chapter 15.6 Points and Lines

2. Gradient of 2 Starter

3. Objective Find the equation of the line perpendicular and passing through the point. Find the gradient of a line

4. Objective 1

5. Wednesday, 07 October 2020 Objective 2: F ind the equation of graphs parallel or perpendicular to others and passing through a specific point. Find the equation of the line perpendicular to y = - x – 2 and passing through the point (2, 9).   What is the gradient of the line given…? y = - x – 2   = -   y = 3x + c   To find the value of c, substitute your pair of coordinates into the equation… sub ( 2 , 9 )  y = 3x + c 9 = 3( 2 ) + c 9 = 6 + c 3 = c So, the equation is … y = 3x + 3. …remember the negative reciprocal…!

6. Wednesday, 07 October 2020 Perpendicular Lines. Equations of Perpendicular Lines: Find the equation of the line perpendicular to y = 2x + 4 and passing through the point (3, 7). What is the gradient of the line given…? y = 2x + 4 = 2 y = x + c   To find the value of c, substitute your pair of coordinates into the equation… sub ( 3 , 7 )  7 = ( 3 ) + c   7 = + c   = c   So, the equation is … y = x + .   …remember the negative reciprocal …! = c  

7. Wednesday, 07 October 2020 Activity 1: Perpendicular Lines. Find the equation of the line which is perpendicular to y = x + 1 and passes through (5, 21). Find the equation of the line which is perpendicular to 10y + 5x = 3 and passes through (-7, -1). Find the equation of the line which is perpendicular to 2x = 8 – y and passes through (16, 47). Find the equation of the line which is perpendicular to 6 + 8y = 3x and passes through (12, -37).  

8. Objective 2

9. What is gradient ? Gradient is the measure of how steep a line is. The bigger the gradient, the steeper the line. Introduction: Gradient of Straight Line

10. The way we work out the gradient of any line is by the formula: change in y change in x Gradient =   Gradient =  

11. Find the gradient of the line through each pair of points A) ( 4,0) and (6,6) B) (0,3) and (8,7)

12. Activity 2

13. Homework Page no. 273 Exercise 15F Q1. Choose any 3 sub-questions.