Introduction
What is a straight line?
A line is simply an object in geometry that is characterized under zero width object that extends on both sides.
A straight line is just a line with no curves. So, a line that extends to both sides till infinity is called a straight line.
A straight line consists of functions between two variables.
Task
Exercise
- Attempt to do the calculations on a page or document before moving to evaluation tab.
- You can find an example of how to calculate the equation of a straight line in the process tab.
1. Given a straight line with the equation y=2x+3
- Construct a table of values with -3 < x < 2
- Draw a graph to illustrate the equation
2. Given a straight line with the equation y= -x+3
- Construct a table of values with -2 < x < 5
- Draw a graph
Process
Before attempting to draw the straight line, you will need to calculate the points of the straight line.
To calculate the points of a straight line, you will need to substitute the x and y values into the given equation.
After you have completed all the calculation, you can draw a graph and plot the points for the straight line.
Watch this video below on how to calculate the equations of straight lines.
Evaluation
Let's have a look at the answers for the exercise.
Hopefully you got everything correct.
1. y=2x+3
to calculate the y-values, we have to substitute the x values in. x values given (-3,2)
- y=2(-3)+3
y= -3 ( this will be the first y value on the table).
- y=2(2)+3 x values given (-3,2)
y=7 ( this will be the last value on the table)
| x | -3 | -2 | -1 | 0 | 1 | 2 |
| y | -3 | -1 | 1 | 3 | 5 | 7 |
The following video will show how the straight line will look like for the equation y=2x+3
2. y= -x+3
- y= -(-2)+3
y= 5 ( this will be the first y value on the table) (x values given -2,5)
| x | -2 | -1 | 0 | 1 | 2 | 3 | 4 | 5 |
| y | 5 | 4 | 3 | 2 | 1 | 0 | -1 | -2 |
The following video will show how the straight line will look for the equation y= -x+3
Conclusion
Well done!
Now you know how to calculate the equation of straight lines.
I hope you learned something valuable today. You should keep practicing to improve your calculation skills!
Credits
Teacher Page
if you have any difficulties with straight lines after this lesson please follow the link below.
https://www.mathsisfun.com/equation_of_line.html
this will explain straight lines further in dept.