Question

Find the angle between the x-axis and the line joining the points (3, -1) and (4, -2).

Answer 1

The slope of the line joining the points (3, -1) and (4, -2) is:
$m = \frac {-2-(-1)}{4-3} = -2+1 = -1$
Now, the inclination (θ) of the line joining the points (3, -1) and (4, -2) is given by:
$tan \ θ= -1$
⇒ $θ = (90°+ 45°) = 135°$
Thus, the angle between the x-axis and the line joining the points (3, -1) and (4, -2) is 135°.