Question

What is the equation of a line, in general form, with a point $\left(-3,0\right)$ and an undefined slope?

• A. $x+3=0$
• B. $y+3=0$
• C. $x-3=0$
• D. $y-3=0$

Answer 1

The correct option is A

$x+3=0$

Explanation for the correct option:

Option (a): the equation of a line, in general form, with a point $\left(-3,0\right)$ with an undefined slope

A vertical line with an undefined slope does not have a $y$-intercept. So, a line with an undefined slope has the equation of the type $x=a$, where $a$ is the $x$-intercept.

Since the point is given as $\left(-3,0\right)$.

So, the equation of the line is $x=-3$.

$\Rightarrow x+3=0$

Hence, option (A) is correct.

The explanation for the incorrect options:

Options (B), (C), and (D): Since the equation of the line is $x+3=0$, options (B), (C), and (D) do not hold true.

Therefore, options (B), (C), and (D are incorrect.

Hence, option (A) is correct.