1. Drawing Graphs from Equations Monday, 21 March 2016 A graph can be drawn from an equation. For example, draw the graph of: y = 2x + 1 This is the equation or RULE for drawing the graph

2. This is the graph of y = 2x + 1 x 01234 2x 02468 2x + 1 13579 y 13579

3. To draw the graph of y = 2x + 1 draw a table like this putting in the x numbers 0 - 4 x 01234

4. x 01234 2x 02468 I want to find y = 2x + 1, so first, you find the value of the 2x. This means 2 X x so times each of the x numbers by 2.

5. x 01234 2x 02468 2x + 1 13579 add on 1 to the 2x Remember, you want to find y = 2x + 1 so you add on 1 to the 2x to find the value of 2x + 1

6. x 01234 2x 02468 2x + 1 13579 y 13579 You have done everything to the x number so now you have found the y number y = 2x + 1

7. x 01234 2x 02468 2x + 1 13579 y 13579 Now, plot the value of x against the value of y on the graph’s axes.

8. x 01234 2x 02468 2x + 1 13579 y 13579 Join up the points with a line

9. x 01234 2x 02468 2x + 1 13579 y 13579 You can draw any graph in a similar way. y= 2x + 1

10. To draw the graph of y = 3x - 5 draw a table like this putting in the x numbers 0 - 4 x 01234 Draw the graph of: y = 3x - 5

11. Find the value of 3x. You times all the x numbers by 3. x 01234 3x 036912 Draw the graph of: y = 3x - 5

12. Take away 5 from the value of 3x. x 01234 3x 036912 3x - 5 -5-2147 Draw the graph of: y = 3x - 5

13. You have done all that the rule asks so you have the y value. x 01234 3x 036912 3x - 5 -5-2147 y -5-2147 Draw the graph of: y = 3x - 5

14. Plot the points x01234 3x036912 3x - 5-5-2147 y-5-2147 Draw the graph of: y = 3x - 5

15. Join up the points with a straight line x01234 3x036912 3x - 5-5-2147 y-5-2147 Draw the graph of: y = 3x - 5

16. Draw the graph of y = 6 – 2x x 01234 Draw a chart with x values 0 to 4

17. Draw the graph of y = 6 – 2x x 01234 2x 02468 Find the value of 2x

18. Draw the graph of y = 6 – 2x x 01234 2x 02468 6 – 2x 6420-2 Take 2x away from 6

19. Draw the graph of y = 6 – 2x x 01234 2x 02468 6 – 2x 6420-2 y 6420 You have done all that the rule asks so you have the y value.

20. Draw the graph of y = 6 – 2x x01234 2x02468 6 – 2x6420-2 y6420 Now, you can plot the points and draw the graph.