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

Explanation

The slope of the line joining the points (3,−1) and (4,−2) is
` m= -2-(-1) div (4-3)= -1`


Now the inclination `theta` of the line joining the points (3,1) and (4,2) is given by,
`tan theta =-1`


` theta = (90^@ + 45^@) = 135^@`


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