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

The Slope of the line joining the points (3, -1) and (4, -2) is

The angle of inclination of 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°.