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Question
Find the angle between the x-axis and the line joining the points (3, –1) and (4, –2).
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Solution
The slope of the line joining the points (3, –1) and (4, –2) is:
m = `(-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°.
Angle between the line and the x-axis 45∘
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