Question

How do you graph the equation by plotting points \[y + 2 = 0\]

Answer 1

Hint: We write the given equation of line by writing the coefficient of the x-axis as 0. Substitute the value of points one by one after attaining the equation or value of y in terms of x. Put different values of x and find values of y.
* General equation of line in x-y plane is given by \[Ax + By + C = 0\]

Complete step-by-step answer:
We are given the equation \[y + 2 = 0\]
We see that there is no x-variable present in the equation, so we can say the x-coordinate is 0 here.
Also, we can write the equation as \[0.x + y + 2 = 0\]
Now we will shift the values except y to right side of the equation such that we obtain the value of y in terms of x
Shift all values except y to RHS of the equation
\[ \Rightarrow y = - 2 - 0.x\] … (1)
Now we substitute some values of x and calculate the respective values of y.
Put \[x = 0\] then we get \[y = - 2\]
Put \[x = 1\] then we get \[y = - 2\]
Put \[x = 2\] then we get \[y = - 2\] and so on
We can see that be any value of ‘x’, we always get the value of y as -2
Now we plot some points on the graph so we can plot the graph of the equation
Plot points \[A(0, - 2);B(1, - 2);C(2, - 2)\]
The line formed by joining the points will be \[y + 2 = 0\]. The line is marked as a bold line in the graph.

Note:
Many students make the mistake of assuming the coefficient of x as 1 and then find the values of y and x accordingly which is wrong. Keep in mind the variable which is not present in the equation means that we have the coefficient of that variable as 0.