Question

The distance between two straight lines $y=mx+c_1$ and $y=mx+c_2$ is $|c_1-c_2|$. Then the value of $m$ is

• A. $1$
• B. $-1$
• C. $0$
• D. none of these

Answer 1

The correct option is C $0$

Given the distance between two straight lines $y=mx+c_1$....(1) and $y=mx+c_2$ is $|c_1-c_2|$.....(2).

Now we have the distance between the two lines is $\left|\frac{c_1-c_2}{\sqrt{1+m^2}}\right|$.

According to the problem,

$|c_1-c_2|=$$\left|\frac{c_1-c_2}{\sqrt{1+m^2}}\right|$

or, $\sqrt{1+m^2}=\pm 1$

or, $1+m^2=1$

or, $m^2=0$

or, $m=0$.