Question

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

Answer 1

Let the given points be A (3, −1) and B (4, −2).

$$\therefore$$ Slope of AB = $$\frac{-2+1}{4-3}=-1$$ 

Let $$\theta$$ be the angle between the x-axis and AB.

$$\therefore \tan \theta =-1$$

$$\Rightarrow \theta ={\tan }^{-1}(-1)=\frac{3\pi }{4}$$

Hence, the angle between the x-axis and the line joining the points (3, −1) and (4, −2) is $$\frac{3\pi }{4}$$.