Step-by-step explanation:
From the figure , assume that OAB is a right angle triangle and angle OAB is alpha
[tex]Slope = \tan( \alpha ) [/tex]
[tex] = \frac{opposite \: side}{adjacent \: side} [/tex]
[tex] = \frac{ - 3}{ - 1} [/tex]
[tex] = 3[/tex]
