Answer: undefined
Step-by-step explanation:
slope form: [tex]\frac{y2 - y1}{x2 - x1}[/tex]
simply plug in values
[tex]\frac{4-1}{-1-(-1)}[/tex]
[tex]\frac{3}{0}[/tex]
Answer: undefined
you can also tell by realizing both x coords are the same, meaning the line is verticle and verticle lines' slopes are undefined