Question

The slope of any line which is parallel to x-axis is …………. .
A.0
B.1
C.-1
D.2

Answer 1

Hint: In this question we are asked to find the slope of a straight line which is parallel to x-axis. But, here we didn’t get any coordinates or equations in the question. So, we will try to find it by drawing a straight line on the graph and find the slope by using formula of ${\displaystyle \frac{y_2-y_1}{x_2-x_1}}$ to get the answer.

Complete step-by-step answer:
Here, we need to find the slope of any line which is parallel to x-axis.
Let us draw a straight line AB on the graph which is parallel to x-axis.

In this graph, the horizontal line is x-axis and the vertical line is y-axis.
By drawing the straight line on the graph we get two points A and B where $(x_1,y_1)$is A$(-3,2)$ and $(x_2,y_2)$is B$(5,2)$ .
Now, we can find the slope of the straight line parallel to the x-axis by taking A and B in the formula of slope.
i.e. ${\displaystyle \frac{y_2-y_1}{x_2-x_1}}$.
Put, $A=(x_1,y_1)=(-3,2)$ and $B=(x_2,y_2)=(5,2)$
$\begin{array}{rl}& \text{slope}={\displaystyle \frac{y_2-y_1}{x_2-x_1}}\\ & ={\displaystyle \frac{2-2}{5-(-3)}}\\ & ={\displaystyle \frac{0}{8}}\\ & =0\end{array}$
By this we get to know that the slope of any straight line parallel to the x-axis is 0.
Therefore, option (a) is the correct answer.
Note: Generally students get confused while solving such types of questions and they may make mistakes while taking x and y coordinates. They should know that y coordinates of the straight line parallel to x-axis will always be the same. Students can solve this problem logically. The slope of a straight line parallel to the x-axis will always be ‘0’ as there will be no slope to the straight line which is parallel to the axis.