Mathematics
For the pair of linear equations given below, draw graphs and then state, whether the lines drawn are parallel or perpendicular to each other.
y = x - 3
y = - x + 5
Answer
First equation = y = x - 3
Step 1:
Give at least three suitable values to the variable x and find the corresponding values of y.
Let x = -1, then y = (-1) - 3 ⇒ y = - 4
Let x = 0, then y = 0 - 3 ⇒ y = - 3
Let x = 1, then y = 1 - 3 ⇒ y = - 2
Let x = 4, then y = 4 - 3 ⇒ y = 1
Step 2:
Make a table (as given below) for the different pairs of the values of x and y:
| x | -1 | 0 | 1 | 4 |
|---|---|---|---|---|
| y | -4 | -3 | -2 | 1 |
Step 3:
Plot the points, from the table, on a graph paper and then draw a straight line passing through the points plotted on the graph.
Second equation = y = - x + 5
Step 1:
Give at least three suitable values to the variable x and find the corresponding values of y.
Let x = -1, then y = - (-1) + 5 ⇒ y = 6
Let x = 0, then y = - 0 + 5 ⇒ y = 5
Let x = 1, then y = - 1 + 5 ⇒ y = 4
Let x = 4, then y = - 4 + 5 ⇒ y = 1
Step 2:
Make a table (as given below) for the different pairs of the values of x and y:
| x | -1 | 0 | 1 | 4 |
|---|---|---|---|---|
| y | 6 | 5 | 4 | 1 |
Step 3:
Plot the points, from the table, on a graph paper and then draw a straight line passing through the points plotted on the graph.

Hence, the two lines are perpendicular to each other.
Related Questions
For the linear equation, given below, draw the graph and then use the graph drawn to find the area of a triangle enclosed by the graph and the co-ordinate axes :
7 - 3 (1 - y) = - 5 + 2x.
For the pair of linear equations given below, draw graphs and then state, whether the lines drawn are parallel or perpendicular to each other.
y = 3x - 1
y = 3x + 2